DINUCLEAR PLATINUM (II) RED EMITTERS FOR OLED APPLICATIONS

Abstract

Platinum (II) complexes (“Pt(II) complexes”) that can emit in the red and/or deep red regions and methods of making and using thereof are described. These Pt(II) complexes can have dinuclearity with close Pt—Pt contact and close interplanar distance, allowing for high emission quantum yield, such as >50%, short emission lifetime, such as <3 μs, and high radiative decay rate, such as in the order of 105 s−1. The Pt(II) complexes disclosed herein can be included in organic light-emitting devices, such as organic light-emitting diodes (“OLEDs”), for use in commercial applications. OLEDs containing these red-emitting Pt(II) complexes can have current efficiency and/or external quantum efficiency that are comparable or higher than commercially available red emitters and prolonged operational lifetime, such as a LT95 at 1000 nits>9000 h for a red OLED.

Description

FIELD OF THE INVENTION

This invention is generally in the field of platinum (II) complexes and their use as red emitters.

BACKGROUND OF THE INVENTION

Transition metal complexes have gained significant interest in commercial and academic settings as molecular probes, catalysts, and luminescent materials. As luminescent materials, transition metal complexes are increasingly being explored as potential alternatives to pure organic-based materials due to their potential for improved luminescence efficiency compared to pure organic-based materials.

There has been growing attention and efforts in adopting luminescent d⁸ planar metal complexes (e.g., Pt(II) and Au(III) complexes) as OLED emitters. However, development of high-efficiency red/deep red emitting Pt(II) complexes is still a challenge. According to the energy gap law, the non-radiative decay rate would increase with decreasing energy gap between the excited state and ground state. The emission quantum yield of red-emitting phosphorescent complexes would be lower than those of blue- and green-emitting phosphorescent complexes, assuming that their radiative decay rates are the same. Currently available red-emitting Pt(II) complexes suffer from low room temperature emission quantum yield (i.e., <50%), long emission lifetime (i.e., >3 μs), and short operational lifetime in OLEDs.

There remains a need for Pt(II) complexes that can emit in the red and/or deep red regions.

Therefore, it is the object of the present invention to provide Pt(II) complexes that emit in the red and/or deep red regions.

It is a further object of the present invention to provide devices containing the Pt(II) complexes that emit in the red and/or deep red regions.

It is a further object of the present invention to provide methods for using the Pt(II) complexes that emit in the red and/or deep red regions.

SUMMARY OF THE INVENTION

Platinum (II) complexes (“Pt(II) complexes”) that can emit in the red and/or deep red regions and methods of making and using thereof are described. These Pt(II) complexes can have dinuclearity with close Pt—Pt contact and close interplanar distance, allowing for high emission quantum yield and high radiative decay rate, such as in the order of 10⁵ s⁻¹.

The Pt(II) complexes can have the structure of Formula I′:

• • where: (a) the compound can have an overall neutral, negative, or positive charge; (b) CY1, CY2, CY3, and CY4 can be independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl; (c) R₁, R₂, R₃, and R₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (d) n1, n2, n3, and n4 can be independently an integer between zero and 10; (e) L₁ and L₃ can be independently a bond (single, double, or triple), absent, oxygen, sulfur, amino, amido, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, carbonyl, sulfonyl, sulfonic acid, phosphoryl, or phosphonyl; (f) R₅, R₆, R₇, and R₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; (g) L₂ and L₄ can be independently a bond (single, double, or triple), substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, amino, amido, or carbonyl; (h) can be absent, a bond (single, double, or triple), a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; and (i) the substituents can be independently a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted alkoxy, a halogen, a hydroxyl, a phenoxy, an aroxy, an alkylthio, a phenylthio, an arylthio, a cyano, an isocyano, a nitro, an carboxyl, an amino, an amido, an oxo, a silyl, a sulfinyl, a sulfonyl, a sulfonic acid, a phosphonium, a phosphanyl, a phosphoryl, a phosphonyl, or a thiol, or a combination thereof.

In some forms, the platinum (II) complex can have the structure of Formula I or I″:

In some forms, the platinum (II) complex can have the structure of Formula II or II′:

• • where: (a) CY2 and CY3 can be independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl; (b) R₂ and R₃ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, amino, alkoxy, or aroxy; (c) n2, n3, n5, and n6 can be independently an integer between zero and 10; (d) R₅, R₆, R₇, and R₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; (e) R₉-R₁₄ and R₂₁-R₂₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (f) G1′ and G2′ can be independently C or N; (g) can be absent, a bond (single, double, or triple), a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; and (h) the substituents can be as defined above for Formula I.

In some forms, the platinum (II) complex can have the structure of Formula III or III′″:

• • where: (a) R₅, R₆, R₇, and R₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; (b) R₉-R₂₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (c) each can be independently absent, a bond (single, double, or triple), a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; (d) X₁′, X₂′, Y₁′, Y₂′, Y₃′, and Y₄′ can be independently O, S, CR₁₅, or NR₁₈, R₁₅ and R₁₈ can be independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; and (e) the substituents can be as defined above for Formula I.

In some forms, the platinum (II) complex can have the structure of Formula IV or IV′:

• • where: (a) R₅, R₆, R₇, and R₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; (b) R₉-R₂₄ and R₂₇-R₃₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (c) each can be independently absent, a bond (single, double, or triple), a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; (d) X₃′ and X₄′ can be independently O, S, CR₂₅, or NR₂₆, R₂₅ and R₂₆ can be independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; and (e) the substituents can be as defined above for Formula I.

In some forms, R₁₁, R₁₂, R₂₁, R₂₂ can be hydrogen or R₁₁ and R₁₂ together can forms and/or R₂₁ and R₂₂ together can form the structure of Formula V:

• • where: (a) Z′ can be O, S, CR₃₉, or NR₄₀, R₃₉ and R₄₀ can be independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (b) J₁′ and J₂′ can be independently

R₄₁ and R₄₂ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol, and optionally J₁′ and J₂′ together form a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, or a substituted or unsubstituted cycloalkynyl; (c) n7 can be independently an integer from 0 to 4; and (d) R₃₅-R₃₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol.

In some forms, the between R₅ and R₈, between R₆ and R₇, between R₅ and R₇, and/or between R₆ and R₈ can be absent, a single bond, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether. In some forms,

can have a structure:

where: (a) A′ and B′ can be independently substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl; and (b) each occurrence of L₅ can be independently ether, polyether, alkoxyl, thioether, sulfonyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, or substituted or unsubstituted alkynyl. In some forms, A′ and B′ can be independently substituted or unsubstituted aryl or substituted or unsubstituted polyaryl; and L₅ can have a structure:

where: (a) Q₁′ and Q₂′ can be independently O or S; and (b) n9 can be an integer from 1 to 10, such as from 1 to 6, e.g. 1, 2, or 6.

The Pt(II) complexes disclosed herein can be included in organic light-emitting devices, such as organic light-emitting diodes (“OLEDs”), for use in commercial applications.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1F are schematics showing the X-ray crystal structures of Pt(II) complexes 1a (FIG. 1A), 1b (FIG. 1B), 3a (FIG. 1C), 3b (FIG. 1D), 1c (FIG. 1E), and 2b′ (FIG. 1F).

FIGS. 2A-2H are graphs showing the emission spectra of Pt(II) complex 1a and 1b in PMMA (FIG. 2A) and MCP (FIG. 2B) films, Pt(II) complex 1b-1d and 1b′-1d′ in PMMA (FIG. 2C) and MCP (FIG. 2D) films, Pt(II) complex 2a-4a and 3b in PMMA (FIG. 2E) and MCP (FIG. 2F) films, and Pt(II) complex 2b and 2b′ in CH₂Cl₂ (FIG. 2G) and PMMA (FIG. 2H), at room temperature.

FIGS. 3A-3D are graphs showing the electrochemiluminescence (“EL”) spectra (FIG. 3A), external quantum efficiency (FIG. 3B), luminance (FIG. 3C), and current density (FIG. 3D) of devices (system I) containing Pt(II) complex 1a at doping concentrations of 6 wt %, 8 wt %, 10 wt %, and 12 wt %. System I device structure: ITO/HAT-CN (5 nm)/TAPC (20 nm)/Tris-PCz (10 nm)/Tris-PCz:B4PYPPM:Pt-1a (30 nm)/B4PYPPM (50 nm)/Liq (1 nm)/Al (100 nm).

FIGS. 4A-4D are graphs showing the EL spectra (FIG. 4A), external quantum efficiency (FIG. 4B), luminance (FIG. 4C), and current density (FIG. 4D) of devices (system II) containing Pt(II) complex 1a at doping concentrations of 4 wt %, 8 wt %, 12 wt %, and 16 wt %. System II device structure: ITO/HAT-CN (5 nm)/TAPC (40 nm)/TCTA (10 nm)/TCTA:TPBi:Pt-1a/TPBi (10 nm)/TmPyPb(40 nm)/LiF (1.2 nm)/Al (100 nm).

FIGS. 5A-5D are graphs showing the EL spectra (FIG. 5A), external quantum efficiency (FIG. 5B), luminance (FIG. 5C), and current density (FIG. 5D) of devices containing Pt(II) complex 1b at doping concentrations of 4 wt %, 12 wt %, and 16 wt %. Device structure: ITO/HAT-CN (5 nm)/TAPC (40 nm)/TCTA (10 nm)/TCTA:TPBi:Pt-1b (20 nm)/TPBi (40 nm)/LiF (1.2 nm)/Al (100 nm).

FIGS. 6A-6B are graphs showing the EL spectra (FIG. 6A) and external quantum efficiency (FIG. 6B) of devices containing Pt(II) complex 1d′ at doping concentrations of 4 wt %. Device structure: ITO/HAT-CN (5 nm)/TAPC (40 nm)/TCTA (10 nm)/Pt-1d′:TCTA:TPBi (20 nm)/TPBi (10 nm)/TmPyPb (40 nm)/LiF (1.2 nm)/Al (100 nm).

FIGS. 7A-7D are graphs showing the EL spectra (FIG. 7A), external quantum efficiency (FIG. 7B), radiant flux (FIG. 7C), current density (FIG. 7D), external quantum efficiency (FIG. 7E), and luminance (FIG. 7F) of devices containing Pt(II) complex 2a at a doping concentration of 6 wt % and electron transport layer (“ETL”) of 40 nm, 80 nm, 100 nm, and 120 nm. Device structure: ITO/HAT-CN (6 nm)/TAPC (40 nm)/TcTa (10 nm)/Pt-2a (6 wt %):TcTa:TPBi (1:1) (20 nm)/TPBi (10 nm)/Liq:LE-T321 (1:1) (ETL)/Liq (1 nm)/Al (100 nm).

FIGS. 8A-8D are graphs showing the EL spectra (FIG. 8A), external quantum efficiency (FIG. 8B), luminance (FIG. 8C), and current density (FIG. 8D) of devices containing Pt(II) complex 2a at doping concentrations of 4 wt %, 8 wt %, 12 wt %, and 16 wt %. Device structure: ITO/HAT-CN (10 nm)/Pt-2a (40 nm)/Compound-EB (5 nm)/Pt-2a:Compound-RH (40 nm)/Compound-HB (5 nm)/Compound-ET:Liq (35:65) (35 nm)/Liq (1 nm)/Al (100 nm).

FIGS. 9A-9D are graphs showing the EL spectra (FIG. 9A), external quantum efficiency (FIG. 9B), radiant flux (FIG. 9C), and current density (FIG. 9D) of devices containing Pt(II) complex 4a at a doping concentration of 6 wt % and ETL of 40 nm, 80 nm, 100 nm, and 120 nm. Device structure: ITO/HAT-CN (6 nm)/TAPC (40 nm)/TcTa (10 nm)/Pt-4a (6 wt %):TcTa:TPBi (1:1) (20 nm)/TPBi (10 nm)/Liq:LE-T321 (1:1) (ETL)/Liq (1 nm)/Al (100 nm).

FIG. 10 is a graph showing the device lifetime measurement results of vapor-deposited devices with Pt(II) complex 1a at doping concentrations of 8 wt %, 12 wt %, and 16 wt %.

FIG. 11 is a graph showing the device lifetime measurement results of vapor-deposited devices with Pt(II) complex 1d′ at a doping concentration of 4 wt %. Device structure: ITO/HAT-CN (10 nm)/PT-301 (40 nm)/Compound-EB (5 nm)/Pt-1d′ (4 wt %): Compound-RH (40 nm)/Compound-HB (5 nm)/Compound-ET:Liq (35:65) (35 nm)/Liq (1 nm)/Al (100 nm).

FIG. 12 is a graph showing the device lifetime measurement results of vapor-deposited devices with Pt(II) complex 2a at doping concentrations of 4 wt %, 8 wt %, 12 wt %, and 16 wt %.

FIG. 13 is a scheme illustrating a non-limiting example of an organic light-emitting diode device, 100, having a multilayer architecture.

FIGS. 14A-14B are graphs showing the EL spectra (FIG. 14A) and external quantum efficiency (FIG. 14B) of vapor-deposited devices containing Pt(II) complex 1c at a doping concentrations of 4 wt %, 8 wt %, and 16 wt %, respectively. Device structure: ITO/HAT-CN (5 nm)/TAPC (40 nm)/TCTA (10 nm)/Pt-1c: TCTA:TPBi (20 nm)/TPBi (10 nm)/TmPyPb (40 nm)/LiF (1.2 nm)/Al (100 nm).

FIGS. 15A-15D are graphs showing the EL spectra (FIG. 15A), external quantum efficiency (FIG. 15B), current density (FIG. 15C), and luminance (FIG. 15D) of vapor-deposited devices containing Pt(II) complex 2b′ at a doping concentrations of 4 wt %, 8 wt %, and 16 wt %, respectively. Device structure: ITO/HAT-CN (5 nm)/TAPC (40 nm)/TCTA (10 nm)/Pt-2b′: TCTA:TPBi (20 nm)/TPBi (10 nm)/TmPyPb (40 nm)/LiF (1.2 nm)/Al (100 nm).

FIG. 16 is a graph showing the lifetime measurement results for OLED containing Pt(II) complex 1b.

FIG. 17 is a graph showing the lifetime measurement results for OLED containing Pt(II) complex 1c.

FIG. 18 is a graph showing the lifetime measurement results for OLED containing Pt(II) complex 2b′.

DETAILED DESCRIPTION OF THE INVENTION

I. Definitions

It is to be understood that the disclosed complexes, compositions, and methods are not limited to specific synthetic methods, specific analytical techniques, or to particular reagents unless otherwise specified, and, as such, may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular forms and embodiments only and is not intended to be limiting.

“Substituted,” as used herein, refers to all permissible substituents of the compounds or functional groups described herein. In the broadest sense, the permissible substituents include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, aromatic and nonaromatic substituents of organic compounds. Illustrative substituents include, but are not limited to, halogens, hydroxyl groups, or any other organic groupings containing any number of carbon atoms, preferably 1-14 carbon atoms, and optionally include one or more heteroatoms such as oxygen, sulfur, or nitrogen grouping in linear, branched, or cyclic structural formats. Representative substituents include a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted phenyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a halogen, a hydroxyl, an alkoxy, a phenoxy, an aroxy, a silyl, a thiol, an alkylthio, a substituted alkylthio, a phenylthio, an arylthio, a cyano, an isocyano, a nitro, a substituted or unsubstituted carbonyl, a carboxyl, an amino, an amido, an oxo, a sulfinyl, a sulfonyl, a sulfonic acid, a phosphonium, a phosphanyl, a phosphoryl, a phosphonyl, an amino acid. Such a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted phenyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a halogen, a hydroxyl, an alkoxy, a phenoxy, an aroxy, a silyl, a thiol, an alkylthio, a substituted alkylthio, a phenylthio, an arylthio, a cyano, an isocyano, a nitro, a substituted or unsubstituted carbonyl, a carboxyl, an amino, an amido, an oxo, a sulfinyl, a sulfonyl, a sulfonic acid, a phosphonium, a phosphanyl, a phosphoryl, a phosphonyl, and an amino acid can be further substituted.

Heteroatoms such as nitrogen may have hydrogen substituents and/or any permissible substituents of organic compounds described herein which satisfy the valences of the heteroatoms. It is understood that “substitution” or “substituted” includes the implicit proviso that such substitution is in accordance with permitted valence of the substituted atom and the substituent, and that the substitution results in a stable compound, i.e. a compound that does not spontaneously undergo transformation such as by rearrangement, cyclization, elimination, etc.

“Alkyl,” as used herein, refers to the radical of saturated aliphatic groups, including straight-chain alkyl groups, branched-chain alkyl, and cycloalkyl (alicyclic). In some forms, a straight chain or branched chain alkyl has 30 or fewer carbon atoms in its backbone (e.g., C₁-C₃₀ for straight chains, C₃-C₃₀ for branched chains), 20 or fewer, 15 or fewer, or 10 or fewer. Alkyl includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, decyl, tetradecyl, hexadecyl, eicosyl, tetracosyl and the like. Likewise, a cycloalkyl is a non-aromatic carbon-based ring composed of at least three carbon atoms, such as a nonaromatic monocyclic or nonaromatic polycyclic ring containing 3-30 carbon atoms, 3-20 carbon atoms, or 3-10 carbon atoms in their ring structure, and have 5, 6 or 7 carbons in the ring structure. Cycloalkyls containing a polycyclic ring system can have two or more non-aromatic rings in which two or more carbons are common to two adjoining rings (i.e., “fused cycloalkyl rings”). Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctanyl, etc.

The term “alkyl” as used throughout the specification, examples, and claims is intended to include both “unsubstituted alkyls” and “substituted alkyls,” the latter of which refers to alkyl moieties having one or more substituents replacing a hydrogen on one or more carbons of the hydrocarbon backbone. Such substituents can be any substituents described above, e.g., halogen (such as fluorine, chlorine, bromine, or iodine), hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), aryl, alkoxyl, aralkyl, phosphonium, phosphanyl, phosphonyl, phosphoryl, phosphate, phosphonate, a phosphinate, amino, amido, amidine, imine, cyano, nitro, azido, oxo, sulfhydryl, thiol, alkylthio, silyl, sulfinyl, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, an aromatic or heteroaromatic moiety. —NRR′, wherein R and R′ are independently hydrogen, alkyl, or aryl, and wherein the nitrogen atom is optionally quaternized; —SR, wherein R is a phosphonyl, a sulfinyl, a silyl a hydrogen, an alkyl, or an aryl; —CN; —NO₂; —COOH; carboxylate; —COR, —COOR, or —CON(R)₂, wherein R is hydrogen, alkyl, or aryl; imino, silyl, ether, haloalkyl (such as —CF3, —CH₂—CF₃, —CCl₃); —CN; —NCOCOCH₂CH₂; —NCOCOCHCH; and —NCS; and combinations thereof. The term “alkyl” also includes “heteroalkyl”.

It will be understood by those skilled in the art that the moieties substituted on the hydrocarbon chain can themselves be substituted, if appropriate. For instance, the substituents of a substituted alkyl may include halogen, hydroxy, nitro, thiols, amino, aralkyl, azido, imino, amido, phosphonium, phosphanyl, phosphoryl (including phosphonate and phosphinate), oxo, sulfonyl (including sulfate, sulfonamido, sulfamoyl and sulfonate), and silyl groups, as well as ethers, alkylthios, carbonyls (including ketones, aldehydes, carboxylates, and esters), haloalkyls, —CN and the like. Cycloalkyls can be substituted in the same manner.

Unless the number of carbons is otherwise specified, “lower alkyl” as used herein means an alkyl group, as defined above, but having from one to ten carbons, more preferably from one to six carbon atoms in its backbone structure. Likewise, “lower alkenyl” and “lower alkynyl” have similar chain lengths.

“Heteroalkyl,” as used herein, refers to straight or branched chain, or cyclic carbon-containing alkyl radicals, or combinations thereof, containing at least one heteroatom. Suitable heteroatoms include, but are not limited to, O, N, Si, P and S, wherein the nitrogen, phosphorous and sulfur atoms are optionally oxidized, and the nitrogen heteroatom is optionally quaternized. For example, the term “heterocycloalkyl group” is a cycloalkyl group as defined above where at least one of the carbon atoms of the ring is substituted with a heteroatom such as, but not limited to, nitrogen, oxygen, sulphur, or phosphorus.

The term “alkenyl” as used herein is a hydrocarbon group of from 2 to 24 carbon atoms and structural formula containing at least one carbon-carbon double bond. Alkenyl groups include straight-chain alkenyl groups, branched-chain alkenyl, and cycloalkenyl. A cycloalkenyl is a non-aromatic carbon-based ring composed of at least three carbon atoms and at least one carbon-carbon double bond, such as a nonaromatic monocyclic or nonaromatic polycyclic ring containing 3-30 carbon atoms and at least one carbon-carbon double bond, 3-20 carbon atoms and at least one carbon-carbon double bond, or 3-10 carbon atoms and at least one carbon-carbon double bond in their ring structure, and have 5, 6 or 7 carbons and at least one carbon-carbon double bond in the ring structure. Cycloalkenyls containing a polycyclic ring system can have two or more non-aromatic rings in which two or more carbons are common to two adjoining rings (i.e., “fused cycloalkenyl rings”) and contain at least one carbon-carbon double bond. Asymmetric structures such as (AB)C=C(C′D) are intended to include both the E and Z isomers. This may be presumed in structural formulae herein wherein an asymmetric alkene is present, or it may be explicitly indicated by the bond symbol C. The term “alkenyl” as used throughout the specification, examples, and claims is intended to include both “unsubstituted alkenyls” and “substituted alkenyls,” the latter of which refers to alkenyl moieties having one or more substituents replacing a hydrogen on one or more carbons of the hydrocarbon backbone. The term “alkenyl” also includes “heteroalkenyl”.

The term “substituted alkenyl” refers to alkenyl moieties having one or more substituents replacing one or more hydrogen atoms on one or more carbons of the hydrocarbon backbone. Such substituents can be any substituents described above, e.g., halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, oxo, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, polyaryl, polyheteroaryl, and combinations thereof.

“Heteroalkenyl,” as used herein, refers to straight or branched chain, or cyclic carbon-containing alkenyl radicals, or combinations thereof, containing at least one heteroatom. Suitable heteroatoms include, but are not limited to, O, N, Si, P and S, wherein the nitrogen, phosphorous and sulfur atoms are optionally oxidized, and the nitrogen heteroatom is optionally quarternized. For example, the term “heterocycloalkenyl group” is a cycloalkenyl group where at least one of the carbon atoms of the ring is substituted with a heteroatom such as, but not limited to, nitrogen, oxygen, sulphur, or phosphorus.

The term “alkynyl group” as used herein is a hydrocarbon group of 2 to 24 carbon atoms and a structural formula containing at least one carbon-carbon triple bond. Alkynyl groups include straight-chain alkynyl groups, branched-chain alkynyl, and cycloalkynyl. A cycloalkynyl is a non-aromatic carbon-based ring composed of at least three carbon atoms and at least one carbon-carbon triple bond, such as a nonaromatic monocyclic or nonaromatic polycyclic ring containing 3-30 carbon atoms and at least one carbon-carbon triple bond, 3-20 carbon atoms and at least one carbon-carbon triple bond, or 3-10 carbon atoms and at least one carbon-carbon triple bond in their ring structure, and have 5, 6 or 7 carbons and at least one carbon-carbon triple bond in the ring structure. Cycloalkynyls containing a polycyclic ring system can have two or more non-aromatic rings in which two or more carbons are common to two adjoining rings (i.e., “fused cycloalkynyl rings”) and contain at least one carbon-carbon triple bond. Asymmetric structures such as (AB)C≡C(C″D) are intended to include both the E and Z isomers. This may be presumed in structural formulae herein wherein an asymmetric alkyne is present, or it may be explicitly indicated by the bond symbol C. The term “alkynyl” as used throughout the specification, examples, and claims is intended to include both “unsubstituted alkynyls” and “substituted alkynyls,” the latter of which refers to alkynyl moieties having one or more substituents replacing a hydrogen on one or more carbons of the hydrocarbon backbone. The term “alkynyl” also includes “heteroalkynyl”.

The term “substituted alkynyl” refers to alkynyl moieties having one or more substituents replacing one or more hydrogen atoms on one or more carbons of the hydrocarbon backbone. Such substituents can be any substituents described above, e.g., halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, polyaryl, polyheteroaryl, and combinations thereof.

“Heteroalkynyl,” as used herein, refers to straight or branched chain, or cyclic carbon-containing alkynyl radicals, or combinations thereof, containing at least one heteroatom. Suitable heteroatoms include, but are not limited to, O, N, Si, P and S, wherein the nitrogen, phosphorous and sulfur atoms are optionally oxidized, and the nitrogen heteroatom is optionally quaternized. For example, the term “heterocycloalkynyl group” is a cycloalkynyl group where at least one of the carbon atoms of the ring is substituted with a heteroatom such as, but not limited to, nitrogen, oxygen, sulphur, or phosphorus.

The term “aryl” as used herein is any C₅-C₂₆ carbon-based aromatic group, heteroaromatic, fused aromatic, or fused heteroaromatic. For example, “aryl,” as used herein can include 5-, 6-, 7-, 8-, 9-, 10-, 14-, 18-, and 24-membered single-ring aromatic groups, including, but not limited to, benzene, naphthalene, anthracene, phenanthrene, chrysene, pyrene, corannulene, coronene, etc. “Aryl” further encompasses polycyclic ring systems having two or more cyclic rings in which two or more carbons are common to two adjoining rings (i.e., “fused aromatic rings”), wherein at least one of the rings is aromatic, e.g., the other cyclic ring or rings can be cycloalkyls, cycloalkenyls, cycloalkynyls, aryls and/or heterocycles. The aryl group can be substituted with one or more groups including, but not limited to, alkyl, alkynyl, alkenyl, aryl, halide, nitro, amino, ester, ketone, aldehyde, hydroxy, carboxylic acid, or alkoxy.

The term “substituted aryl” refers to an aryl group, wherein one or more hydrogen atoms on one or more aromatic rings are substituted with one or more substituents. Such substituents can be any substituents described above, e.g., halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, alkoxy, carbonyl (such as a ketone, aldehyde, carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, imino, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl (such as CF3, —CH₂—CF₃, —CCl₃), —CN, aryl, heteroaryl, and combinations thereof.

“Heterocycle” and “heterocyclyl” are used interchangeably, and refer to a cyclic radical attached via a ring carbon or nitrogen atom of a non-aromatic monocyclic or polycyclic ring containing 3-30 ring atoms, 3-20 ring atoms, 3-10 ring atoms, or 5-6 ring atoms, where each ring contains carbon and one to four heteroatoms each selected from the group consisting of non-peroxide oxygen, sulfur, and N(Y) wherein Y is absent or is H, O, C₁-C₁₀ alkyl, phenyl or benzyl, and optionally containing 1-3 double bonds and optionally substituted with one or more substituents. Heterocyclyl are distinguished from heteroaryl by definition. Heterocycles can be a heterocycloalkyl, a heterocycloalkenyl, a heterocycloalkynyl, etc, such as piperazinyl, piperidinyl, piperidonyl, 4-piperidonyl, dihydrofuro[2,3-b]tetrahydrofuran, morpholinyl, piperazinyl, piperidinyl, piperidonyl, 4-piperidonyl, piperonyl, pyranyl, 2H-pyrrolyl, 4H-quinolizinyl, quinuclidinyl, tetrahydrofuranyl, 6H-1,2,5-thiadiazinyl. Heterocyclic groups can optionally be substituted with one or more substituents as defined above for alkyl and aryl.

The term “heteroaryl” refers to C₅-C₃₀-membered aromatic, fused aromatic, biaromatic ring systems, or combinations thereof, in which one or more carbon atoms on one or more aromatic ring structures have been substituted with a heteroatom. Suitable heteroatoms include, but are not limited to, oxygen, sulfur, and nitrogen. Broadly defined, “heteroaryl,” as used herein, includes 5-, 6-, 7-, 8-, 9-, 10-, 14-, 18-, and 24-membered single-ring aromatic groups that may include from one to four heteroatoms, for example, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole, tetrazole, pyrazole, pyridine, pyrazine, pyridazine and pyrimidine, and the like. The heteroaryl group may also be referred to as “aryl heterocycles” or “heteroaromatics”. “Heteroaryl” further encompasses polycyclic ring systems having two or more rings in which two or more carbons are common to two adjoining rings (i.e., “fused rings”) wherein at least one of the rings is heteroaromatic, e.g., the other cyclic ring or rings can be cycloalkyls, cycloalkenyls, cycloalkynyls, aryls, heterocycles, or combinations thereof. Examples of heteroaryl rings include, but are not limited to, benzimidazolyl, benzofuranyl, benzothiofuranyl, benzothiophenyl, benzoxazolyl, benzoxazolinyl, benzthiazolyl, benztriazolyl, benztetrazolyl, benzisoxazolyl, benzisothiazolyl, benzimidazolinyl, carbazolyl, 4aH-carbazolyl, carbolinyl, chromanyl, chromenyl, cinnolinyl, decahydroquinolinyl, 2H,6H-1,5,2-dithiazinyl, furanyl, furazanyl, imidazolidinyl, imidazolinyl, imidazolyl, 1H-indazolyl, indolenyl, indolinyl, indolizinyl, indolyl, 3H-indolyl, isatinoyl, isobenzofuranyl, isochromanyl, isoindazolyl, isoindolinyl, isoindolyl, isoquinolinyl, isothiazolyl, isoxazolyl, methylenedioxyphenyl, naphthyridinyl, octahydroisoquinolinyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, oxazolidinyl, oxazolyl, oxindolyl, pyrimidinyl, phenanthridinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenoxathinyl, phenoxazinyl, phthalazinyl, pteridinyl, purinyl, pyrazinyl, pyrazolidinyl, pyrazolinyl, pyrazolyl, pyridazinyl, pyridooxazole, pyridoimidazole, pyridothiazole, pyridinyl, pyridyl, pyrimidinyl, pyrrolidinyl, pyrrolinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, tetrazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, thianthrenyl, thiazolyl, thienyl, thienothiazolyl, thienooxazolyl, thienoimidazolyl, thiophenyl and xanthenyl. One or more of the rings can be substituted as defined below for “substituted heteroaryl”.

The term “substituted heteroaryl” refers to a heteroaryl group in which one or more hydrogen atoms on one or more heteroaromatic rings are substituted with one or more substituents. Such substituents can be any substituents described above, e.g., halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, alkoxy, carbonyl (such as a ketone, aldehyde, carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, imino, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl (such as CF3, —CH₂—CF₃, —CCl₃), —CN, aryl, heteroaryl, and combinations thereof.

The term “polyaryl” refers to a chemical moiety that includes two or more aryls, heteroaryls, and combinations thereof. The aryls, heteroaryls, and combinations thereof, are fused, or linked via a single bond, ether, ester, carbonyl, amide, sulfonyl, sulfonamide, alkyl, azo, and combinations thereof. For example, a “polyaryl” can be polycyclic ring systems having two or more cyclic rings in which two or more carbons are common to two adjoining rings (i.e., “fused aromatic rings”), wherein two or more of the rings are aromatic. When two or more heteroaryls are involved, the chemical moiety can be referred to as a “polyheteroaryl.”

The term “substituted polyaryl” refers to a polyaryl in which one or more of the aryls, heteroaryls are substituted, with one or more substituents. Such substituents can be any substituents described above, e.g., halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, and combinations thereof. When two or more heteroaryls are involved, the chemical moiety can be referred to as a “substituted polyheteroaryl.”

The term “cyclic ring” refers to a substituted or unsubstituted monocyclic ring or a substituted or unsubstituted polycyclic ring (such as those formed from single or fused ring systems), such as a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted cycloalkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, and a substituted or unsubstituted polyheteroaryl, that have from three to 30 carbon atoms, as geometric constraints permit. The substituted cycloalkyls, cycloalkenyls, cycloalkynyls, and heterocyclyls are substituted as defined above for the alkyls, alkenyls, alkynyls, heterocyclyls, aryls, heteroaryl, polyaryls, and polyheteroaryls, respectively.

The term “aralkyl” as used herein is an aryl group or a heteroaryl group having an alkyl, alkynyl, or alkenyl group as defined above attached to the aromatic group, such as an aryl, a heteroaryl, a polyaryl, or a polyheteroaryl. An example of an aralkyl group is a benzyl group.

The terms “alkoxyl” or “alkoxy,” “aroxy” or “aryloxy,” generally describe compounds represented by the formula —OR^v, wherein R^v includes, but is not limited to, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocycloalkenyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted arylalkyl, a substituted or unsubstituted heteroalkyl, a substituted or unsubstituted alkylaryl, a substituted or unsubstituted alkylheteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted carbonyl, a phosphonium, a phosphanyl, a phosphonyl, a sulfinyl, a silyl, a thiol, an amido, and an amino. Exemplary alkoxyl groups include methoxy, ethoxy, propyloxy, tert-butoxy and the like. A “lower alkoxy” group is an alkoxy group containing from one to six carbon atoms. An “ether” is two functional groups covalently linked by an oxygen as defined below. Accordingly, the substituent of an alkyl that renders that alkyl an ether is or resembles an alkoxyl, such as can be represented by one of —O-alkyl, —O-alkenyl, —O-alkynyl, —O-aryl, —O-heteroaryl, —O-polyaryl, —O-polyheteroaryl, —O-heterocyclyl, etc.

The term “substituted alkoxy” refers to an alkoxy group having one or more substituents replacing one or more hydrogen atoms on one or more carbons of the alkoxy backbone. Such substituents can be any substituents described above, e.g., halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, oxo, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, and combinations thereof.

The term “ether” as used herein is represented by the formula A²OA¹, where A² and A¹ can be, independently, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a phosphonium, a phosphanyl, a phosphonyl, a sulfinyl, a silyl, a thiol, a substituted or unsubstituted carbonyl, an alkoxy, an amido, or an amino, described above.

The term “polyether” as used herein is represented by the formula:

where A³, A², and A¹ can be, independently, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a phosphonium, a phosphanyl, a substituted or unsubstituted carbonyl, an alkoxy, an amido, or an amino, described above; g can be a positive integer from 1 to 30.

The term “phenoxy” is art recognized, and refers to a compound of the formula —OR wherein R^v is (i.e., —O—C₆H₅). One of skill in the art recognizes that a phenoxy is a species of the aroxy genus.

The term “substituted phenoxy” refers to a phenoxy group, as defined above, having one or more substituents replacing one or more hydrogen atoms on one or more carbons of the phenyl ring. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, and combinations thereof.

The terms “aroxy” and “aryloxy,” as used interchangeably herein, are represented by —O-aryl or —O-heteroaryl, wherein aryl and heteroaryl are as defined herein.

The terms “substituted aroxy” and “substituted aryloxy,” as used interchangeably herein, represent —O-aryl or —O-heteroaryl, having one or more substituents replacing one or more hydrogen atoms on one or more ring atoms of the aryl and heteroaryl, as defined herein. Such substituents can be any substituents described above, e.g., halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, polyaryl, polyheteroaryl, and combinations thereof.

The term “amino” as used herein includes the group

• • wherein, E is absent, or E is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aralkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, wherein independently of E, R^x, R^xi, and R^xii each independently represent a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a phosphonium, a phosphanyl, a phosphonyl, a sulfinyl, a silyl, a thiol, an amido, an amino, or —(CH₂)_m—R′″; R′″ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an alkoxy, a phosphonium, a phosphanyl, an amido, or an amino; and m is zero or an integer ranging from 1 to 8. The term “quaternary amino” also includes the groups where the nitrogen, R^x, R^xi, and R^xii with the N⁺ to which they are attached complete a heterocyclyl or heteroaryl having from 3 to 14 atoms in the ring structure.

The terms “amide” or “amido” are used interchangeably, refer to both “unsubstituted amido” and “substituted amido” and are represented by the general formula:

• • wherein, E is absent, or E is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, or a substituted or unsubstituted heterocyclyl, wherein independently of E, R and R′ each independently represent a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a phosphonium, a phosphanyl, a phosphonyl, a sulfinyl, a silyl, a thiol, an amido, an amino, or —(CH₂)_m—R′″, or R and R′ taken together with the N atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R′″ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an alkoxy, a phosphonium, a phosphanyl, an amido, or an amino; and m is zero or an integer ranging from 1 to 8. In some forms, when E is oxygen, a carbamate is formed.

“Carbonyl,” as used herein, is art-recognized and includes such moieties as can be represented by the general formula:

wherein X is a bond, or represents an oxygen or a sulfur, and R represents a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a phosphonium, a phosphanyl, an amido, an amino, or —(CH₂)_m—R″, or a pharmaceutical acceptable salt; E″ is absent, or E″ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aralkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl; R′ represents a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a phosphonium, a phosphanyl, an amido, an amino, or —(CH₂)_m—R″; R″ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an alkoxy, a phosphonium, a phosphanyl, an amido, or an amino; and m is zero or an integer ranging from 1 to 8. Where X is oxygen and R is defined as above, the moiety is also referred to as a carboxyl group. When X is oxygen and R is hydrogen, the formula represents a “carboxylic acid”. Where X is oxygen and R′ is hydrogen, the formula represents a “formate”. Where X is oxygen and R or R′ is not hydrogen, the formula represents an “ester”. In general, where the oxygen atom of the above formula is replaced by a sulfur atom, the formula represents a “thiocarbonyl” group. Where X is sulfur and R or R′ is not hydrogen, the formula represents a “thioester”. Where X is sulfur and R is hydrogen, the formula represents a “thiocarboxylic acid”. Where X is sulfur and R′ is hydrogen, the formula represents a “thioformate”. Where X is a bond and R is not hydrogen, the above formula represents a “ketone”. Where X is a bond and R is hydrogen, the above formula represents an “aldehyde”.

The term “substituted carbonyl” refers to a carbonyl, as defined above, wherein one or more hydrogen atoms in R, R′ or a group to which the moiety

is attached, are independently substituted. Such substituents can be any substituents described above, e.g., halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, and combinations thereof.

The term “carboxyl” is as defined above for carbonyl and is defined more specifically by the formula —R^ivCOOH, wherein R^iv is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, or a substituted or unsubstituted heteroaryl.

The term “substituted carboxyl” refers to a carboxyl, as defined above, wherein one or more hydrogen atoms in R^iv are substituted. Such substituents can be any substituents described above, e.g., halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, polyaryl, polyheteroaryl, and combinations thereof.

The term “phosphanyl” is represented by the formula

• • wherein, E is absent, or E is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, wherein independently of E, R^vi and R^vii each independently represent a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl, etc.), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a phosphonium, a phosphanyl, a phosphonyl, a sulfinyl, a silyl, a thiol, an amido, an amino, or —(CH₂)_m—R′″, or R^vi and R^vii taken together with the P atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R′″ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an alkoxy, a phosphonium, a phosphanyl, an amido, or an amino; and m is zero or an integer ranging from 1 to 8.

The term “phosphonium” is represented by the formula

• • wherein, E is absent, or E is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, wherein independently of E, R^vi, R^vii, and R^viii each independently represent a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl, etc.), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a phosphonium, a phosphanyl, a phosphonyl, a sulfinyl, a silyl, a thiol, an amido, an amino, or —(CH₂)_m—R′″, or R^vi, R^vii, and R^viii taken together with the P⁺ atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R′″ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an alkoxy, a phosphonium, a phosphanyl, an amido, or an amino; and m is zero or an integer ranging from 1 to 8.

The term “phosphonyl” is represented by the formula

• • wherein E is absent, or E is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aralkyl (e.g., a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl, etc.), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, oxygen, alkoxy, aroxy, or substituted alkoxy or substituted aroxy, wherein, independently of E, R^vi and R^vii are independently a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl, etc.), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a phosphonium, a phosphanyl, a phosphonyl, a sulfinyl, a silyl, a thiol, an amido, an amino, or —(CH₂)_m—R′″, or R^vi and R^vii taken together with the P atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R′″ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an alkoxy, a phosphonium, a phosphanyl, an amido, or an amino; and m is zero or an integer ranging from 1 to 8.

The term “substituted phosphonyl” represents a phosphonyl in which E, R^vi and R^vi are independently substituted. Such substituents can be any substituents described above, e.g., halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, polyaryl, polyheteroaryl, and combinations thereof.

The term “phosphoryl” defines a phosphonyl in which E is absent, oxygen, alkoxy, aroxy, substituted alkoxy or substituted aroxy, as defined above, and independently of E, R^vi and R^vii are independently hydroxyl, alkoxy, aroxy, substituted alkoxy or substituted aroxy, as defined above. When E is oxygen, the phosphoryl cannot be attached to another chemical species, such as to form an oxygen-oxygen bond, or other unstable bonds, as understood by one of ordinary skill in the art. When E, R^vi and R^vii are substituted, the substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, polyaryl, polyheteroaryl, and combinations thereof.

The term “sulfinyl” is represented by the formula

• • wherein E is absent, or E is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aralkyl (e.g., a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl, etc.), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, wherein independently of E, R represents a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a phosphonium, a phosphanyl, a phosphonyl, a silyl, a thiol, an amido, an amino, or —(CH₂)_m—R′″, or E and R taken together with the S atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R′″ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an alkoxy, a phosphonium, a phosphanyl, an amido, or an amino; and m is zero or an integer ranging from 1 to 8.

The term “sulfonyl” is represented by the formula

• • wherein E is absent, or E is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aralkyl (e.g., a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl, etc.), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, wherein independently of E, R represents a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a phosphonium, a phosphanyl, an amido, an amino, or —(CH₂)_m—R′″, or E and R taken together with the S atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R′″ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an alkoxy, a phosphonium, a phosphanyl, an amido, or an amino; and m is zero or an integer ranging from 1 to 8.

The term “substituted sulfonyl” represents a sulfonyl in which E, R, or both, are independently substituted. Such substituents can be any substituents described above, e.g., halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, polyaryl, polyheteroaryl, and combinations thereof.

The term “sulfonic acid” refers to a sulfonyl, as defined above, wherein R is hydroxyl, and E is absent, or E is substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heteroaryl.

The term “sulfate” refers to a sulfonyl, as defined above, wherein E is absent, oxygen, alkoxy, aroxy, substituted alkoxy or substituted aroxy, as defined above, and R is independently hydroxyl, alkoxy, aroxy, substituted alkoxy or substituted aroxy, as defined above. When E is oxygen, the sulfate cannot be attached to another chemical species, such as to form an oxygen-oxygen bond, or other unstable bonds, as understood by one of ordinary skill in the art.

The term “sulfonate” refers to a sulfonyl, as defined above, wherein E is oxygen, alkoxy, aroxy, substituted alkoxy or substituted aroxy, as defined above, and R is independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted amino, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aralkyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, —(CH₂)_m—R′″, R′″ represents a hydroxy group, substituted or unsubstituted carbonyl group, an aryl, a cycloalkyl ring, a cycloalkenyl ring, a heterocycle, an amido, an amino, or a polycycle; and m is zero or an integer ranging from 1 to 8. When E is oxygen, sulfonate cannot be attached to another chemical species, such as to form an oxygen-oxygen bond, or other unstable bonds, as understood by one of ordinary skill in the art.

The term “sulfamoyl” refers to a sulfonamide or sulfonamide represented by the formula

wherein E is absent, or E is substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aralkyl (e.g., a substituted or unsubstituted alkylaryl, a substituted or unsubstituted cycloalkyl, etc.), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, wherein independently of E, R and R′ each independently represent a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl, etc.), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a phosphonium, a phosphanyl, an amido, an amino, or —(CH₂)_m—R′″, or R and R′ taken together with the N atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R′″ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an alkoxy, a phosphonium, a phosphanyl, an amido, or an amino; and m is zero or an integer ranging from 1 to 8.

The terms “thiol” are used interchangeably and are represented by —SR, where R can be a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl, etc.), a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted carbonyl, a phosphonium, a phosphanyl, an amido, an amino, an alkoxy, an oxo, a phosphonyl, a sulfinyl, or a silyl, described above.

The term “alkylthio” refers to an alkyl group, as defined above, having a sulfur radical attached thereto. The “alkylthio” moiety is represented by —S-alkyl. Representative alkylthio groups include methylthio, ethylthio, and the like. The term “alkylthio” also encompasses cycloalkyl groups having a sulfur radical attached thereto.

The term “substituted alkylthio” refers to an alkylthio group having one or more substituents replacing one or more hydrogen atoms on one or more carbon atoms of the alkylthio backbone. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, and combinations thereof.

The term “phenylthio” is art recognized, and refers to —S—C₆H₅, i.e., a phenyl group attached to a sulfur atom.

The term “substituted phenylthio” refers to a phenylthio group, as defined above, having one or more substituents replacing a hydrogen on one or more carbons of the phenyl ring. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, and combinations thereof.

“Arylthio” refers to —S-aryl or —S-heteroaryl groups, wherein aryl and heteroaryl as defined herein.

The term “substituted arylthio” represents —S-aryl or —S-heteroaryl, having one or more substituents replacing a hydrogen atom on one or more ring atoms of the aryl and heteroaryl rings as defined herein. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl), silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate), alkoxyl, phosphonium, phosphanyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (e.g. quarternized amino), amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, —CN, aryl, heteroaryl, and combinations thereof.

Numerical ranges disclosed herein of any type, disclose individually each possible number that such a range could reasonably encompass, as well as any sub-ranges and combinations of sub-ranges encompassed therein.

II. Compositions

Pt(II) complexes that can emit in red and/or deep red regions are described herein. The Pt(II) complexes can contain a dinuclear center and bidentate and/or tetradentatge ligands. These can display red to deep red emissions with emission maxima spanning across 600 nm to 1000 nm (preferably 600 nm to 730 nm) and high emission quantum yield. For example, the Pt(II) complexes disclosed herein show an emission maxima in a range from 600 nm to 730 nm and have a high room temperature emission quantum yield of >50%, such as up to 80%, as measured by absolute measurement methods or relative measurement methods using a standard references, such as Pt(tpdbp), and a short emission lifetime of <3 μs, such as down 10 to 1.3 μs.

Without being bound to any theories, these dinuclear Pt(II) complexes have close Pt—Pt contact of ˜2.85-2.87 Å and close interplanar distance below 3.3 Å. This dinuclearity feature allows enhanced metal character in ³MMLCT (metal-metal-to-ligand charge transfer) excited state, resulting in the high stability, high emission quantum yield, and high radiative decay rate (in the order of 10⁵ s⁻¹) of these Pt(II) complexes. Such a high radiative decay rate outweighs the increased non-radiative decay rate, which is commonly observed in red emitters.

A. Platinum (II) Complexes

The platinum (II) complex can have the structure of Formula I′:

• • where: (a) the compound can have an overall neutral, negative, or positive charge; (b) CY1, CY2, CY3, and CY4 can be independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl; (c) R₁, R₂, R₃, and R₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (d) n1, n2, n3, and n4 can be independently an integer between zero and 10; (e) L₁ and L₃ can be independently a bond (single, double, or triple), absent, oxygen, sulfur, amino, amido, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, carbonyl, sulfonyl, sulfonic acid, phosphoryl, or phosphonyl; (f) R₅, R₆, R₇, and R₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; (g) L₂ and L₄ can be independently a bond (single, double, or triple), substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, amino, amido, or carbonyl; (h) can be absent, a bond (single, double, or triple), a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; and (i) the substituents can be independently a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted alkoxy, a halogen, a hydroxyl, a phenoxy, an aroxy, an alkylthio, a phenylthio, an arylthio, a cyano, an isocyano, a nitro, an carboxyl, an amino, an amido, an oxo, a silyl, a sulfinyl, a sulfonyl, a sulfonic acid, a phosphonium, a phosphanyl, a phosphoryl, a phosphonyl, or a thiol, or a combination thereof.

In some forms, the platinum (II) complex can have the structure of Formula I or I″:

• • where: (a) the compound can have an overall neutral, negative, or positive charge; (b) CY1, CY2, CY3, and CY4 can be independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl; (c) R₁, R₂, R₃, and R₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (d) n1, n2, n3, and n4 can be independently an integer between zero and 10; (e) L₁ and L₃ can be independently a bond (single, double, or triple), absent, oxygen, sulfur, amino, amido, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, carbonyl, sulfonyl, sulfonic acid, phosphoryl, or phosphonyl; (f) R₅, R₆, R₇, and R₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; (g) L₂ and L₄ can be independently a bond (single, double, or triple), substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, amino, amido, or carbonyl; (h) can e absent, a bond (single, double, or triple), a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; and (i) the substituents can be independently a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted alkoxy, a halogen, a hydroxyl, a phenoxy, an aroxy, an alkylthio, a phenylthio, an arylthio, a cyano, an isocyano, a nitro, an carboxyl, an amino, an amido, an oxo, a silyl, a sulfinyl, a sulfonyl, a sulfonic acid, a phosphonium, a phosphanyl, a phosphoryl, a phosphonyl, or a thiol, or a combination thereof.

In some forms, the platinum (II) complexes are isomers having the structure of Formula Ia, Ia′, Ib, or Ib′:

• • where CY1, CY2, CY3, CY4, R₁, R₂, R₃, R₄, n1, n2, n3, n4, L₁, L₃, R₅, R₆, R₇, R₈, L₂, L₄, , and the substituents can be as defined above for Formula I.

In some forms of Formulae I, I′, I″, Ia, Ia′, Ib, and/or Ib′, the platinum (II) complex can have an overall neutral charge. In some forms of Formulae I, Ia, and/or Ib, CY1, CY2, CY3, and CY4 can be independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl.

In some forms, the platinum (II) complex can have the structure of Formula II or II′:

• • where: (a) CY2 and CY3 can be independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl; (b) R₂ and R₃ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, amino, alkoxy, or aroxy; (c) n2, n3, n5, and n6 can be independently an integer between zero and 10; (d) R₅, R₆, R₇, and R₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; (e) R₉ and R₁₀ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (f) R₁₁-R₁₄ and R₂₁-R₂₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol, and optionally R₁₁ and R₁₂ together, R₁₂ and R₁₃ together, R₁₃ and R₁₄ together, R₂₁ and R₂₂ together, R₂₂ and R₂₃ together, and/or R₂₃ and R₂₄ together can form a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted cycloalkynyl, or a substituted or unsubstituted heterocyclyl, such as a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl; (g) G1′ and G2′ can be independently C or N; (h) can be absent, a bond (single, double, or triple), a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; and (i) the substituents can be as defined above for Formula I.

In some forms, the platinum (II) complexes are isomers having the structure of Formula IIa, IIa′, IIb, or IIb′:

• • where CY2, CY3, R₂, R₃, n2, n3, n5, n6, R₅-R₈, R₉-R₁₄, R₂₁-R₂₄, G1′ and G2′, , and the substituents can be as defined above for Formula II.

In some forms of Formulae I, I′, I″, Ia, Ia′, Ib, Ib′, II, II′, IIa, IIa′, IIb, and/or IIb′, CY2 and CY3 can be independently substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl. In some forms of Formulae I, I′, I″, Ia, Ia′, Ib, Ib′, II, II′, IIa, IIa′, IIb, and/or IIb′, n2 and n3 are independently an integer between 2 and 4, and two adjacent R₂ and/or two adjacent R₃ forms a substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl.

In some forms, the platinum (II) complex can have the structure of Formula III′ or

• • where: (a) R₅, R₆, R₇, and R₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; (b) R₉ and R₁₀ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (c) R₁₁-R₁₄ and R₂₁-R₂₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol, and optionally R₁₁ and R₁₂ together, R₁₂ and R₁₃ together, R₁₃ and R₁₄ together, R₂₁ and R₂₂ together, R₂₂ and R₂₃ together, and/or R₂₃ and R₂₄ together can form a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted cycloalkynyl, or a substituted or unsubstituted heterocyclyl, such as a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl; (d) each can be independently absent, a bond (single, double, or triple), a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; (e) X₁′, X₂′, Y₁′-Y₈′ can be independently O, S, CR₁₅, or NR₁₈, R₁₅ and R₁₈ can be independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; and (f) the substituents can be as defined above for Formula I.

In some forms, the platinum (II) complex can have the structure of Formula III or III′″:

• • where: (a) R₅, R₆, R₇, and R₇ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; (b) R₉ and R₁₀ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (c) R₁₁-R₁₄, R₁₉, R₁₇, and R₁₉-R₂₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol, and optionally R₁ and R₁₂ together, R₁₂ and R₁₃ together, R₁₃ and R₁₄ together, R₁₀ and R₁₇ together, R₁₉ and R₂₀ together, R₂₁ and R₂₂ together, R₂₂ and R₂₃ together, and/or R₂₃ and R₂₄ together can form a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted cycloalkynyl, or a substituted or unsubstituted heterocyclyl, such as a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl; (d) each can be independently absent, a bond (single, double, or triple), a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; (e) X₁′, X₂′, Y₁′, Y₂′, Y₃′, and Y₄′ can be independently O, S, CR₁₅, or NR₁₈, R₁₅ and R₁₈ can be independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; and (f) the substituents can be as defined above for Formula I.

In some forms, the platinum (II) complexes are isomers having the structure of Formula IIIa, IIIa′, IIIb, or IIIb′:

• • where R₅-R₂₄, , X₁′, X₂′, Y₁′, Y₂′, Y₃′, Y₄′, and the substituents can be as defined above for Formula III.

In some forms of Formulae III, III′, III″, III′″, IIIa, IIIa′, IIIb, and/or IIIb′, X₁′, X₂′, Y₁′, Y₂′, Y₃′, and Y₄′ can be independently CR₁₅ or NR₁₈, R₁₅ and R₁₈ can be independently absent, hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl. In some forms of Formulae III, III′, IIIa, and/or IIIb, X₁′, X₂′, Y₁′ and/or Y₃′, and Y₂′ and/or Y₄′ can be independently NR₁₈, each occurrence of R₁₈ can be absent, hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl. In some forms of Formulae III, III′, III″, III′″, IIIa, IIIa′, IIIb, and/or IIIb′, R₁₆, R₁₇, R₁₉, and R₂₀ can be independently hydrogen, halogen, nitrile, nitro, amino, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, or hydroxyl, or R₁₆ and R₁₇, R₁₉ and R₂₀, R₂₂ and R₂₃, and/or R₁₂ and R₁₃, together form an substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl. In some forms of Formulae III, III′, III″, III′″, IIIa, IIIa′, IIIb, and/or IIIb′, R₁₆ and R₁₇ and/or R₁₉ and R₂₀, together form an substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl. In some forms of Formulae III, III′, III″, III′″, IIIa, IIIa′, IIIb, and/or IIIb′, R₁₂ and R₁₃ and/or R₂₂ and R₂₃, together form an substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl.

In some forms, the platinum (II) complex can have the structure of Formula IV or IV′:

• • where: (a) R₅, R₆, R₇, and R₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; (b) R₉ and R₁₀ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (c) R₁₁-R₁₄, R₂₁-R₂₄, and R₂₇-R₃₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol, and optionally R₁₁ and R₁₂ together, R₁₂ and R₁₃ together, R₁₃ and R₁₄ together, R₂₁ and R₂₂ together, R₂₂ and R₂₃ together, R₂₃ and R₂₄, R₂₇ and R₂₈ together, R₂₈ and R₂₉ together, R₂₉ and R₃₀ together, R₃₁ and R₃₂ together, R₃₂ and R₃₃ together, and/or R₃₃ and R₃₄ together, can form a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted cycloalkynyl, or a substituted or unsubstituted heterocyclyl, such as a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl; (d) each can be independently absent, a bond (single, double, or triple), a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; (e) X₃′ and X₄′ can be independently CR₂₅ or NR₂₆, R₂₅ and R₂₆ can be independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; and (f) the substituents can be as defined above for Formula I.

In some forms, the platinum (II) complexes are isomers having the structure of Formula IVa, IVa′, IVb, or IVb′:

• • where R₅-R₂₄, R₂₇-R₃₄, , X₃′, X₄′, and the substituents can be as defined above for Formula IV.

In some forms of Formulae IV, IV′, IVa, IVa′, IVb, and/or IVb′, X₃′ and X₄′ can be independently CR₂₅ or NR₂₆, R₂₅ and R₂₆ can be independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl. In some forms of Formulae IV, IVa, and/or IVb, X₃′ and X₄′ can be independently NR₂₆, each occurrence of R₂₆ can be independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl. In some forms of Formulae IV, IV′, IVa, IVa′, IVb, and/or IVb′, R₂₇-R₃₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, or hydroxyl. In some forms of Formulae IV, IV′, IVa, IVa′, IVb, and/or IVb′, R₂₇-R₃₄ can be independently hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl.

In some forms of Formulae II, II′, IIa, IIa′, IIb, IIb′, III, III′, III″, III′″, IIIa, IIIa′, IIIb, IIIb′, IV, IV′, IVa, IVa′, IVb, and/or IVb′, R₉ and R₁₀ can be independently hydrogen or substituted or unsubstituted alkyl. In some forms of Formulae II, II′, IIa, IIa′, IIb, IIb′, III, III′, III″, III′″, IIIa, IIIa′, IIIb, IIIb′, IV, IV′, IVa, IVa′, IVb, and/or IVb′, R₁₁-R₁₄ and R₂₁-R₂₄ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, hydroxyl, alkoxy, or aroxy. In some forms of Formulae II, II′, IIa, IIa′, IIb, IIb′, III, III′, III″, III′″, IIIa, IIIa′, IIIb, IIIb′, IV, IV′, IVa, IVa′, IVb, and/or IVb′, R₁, R₁₂, R₂₁, R₂₂ can be hydrogen or R₁₁ and R₁₂ together can form a substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl and/or R₂₁ and R₂₂ together can form a substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl.

In some forms of Formulae II, II′, IIa, IIa′, IIb, IIb′, III, III′, III″, III′″, IIIa, IIIa′, IIIb, IIIb′, IV, IV′, IVa, IVa′, IVb, and/or IVb′, Ru, R₁₂, R₂₁, R₂₂ can be hydrogen or Ru and R₁₂ together can forms and/or R₂₁ and R₂₂ together can form the structure of Formula V:

• • where: (a) Z′ can be O, S, CR₃₉, or NR₄₀, R₃₉ and R₄₀ can be independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; (b) J₁′ and J₂′ can be independently

R₄₁ and R₄₂ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol, and optionally J₁′ and J₂′ together can form a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, or a substituted or unsubstituted cycloalkynyl; (c) n7 can be independently an integer from 0 to 4; and (d) R₃₅-R₃₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol.

In some forms of Formula V, n7 can be 0 and Z′ can be O, S, or NR₄₀, each occurrence of R₄₀ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, or hydroxyl. In some forms of Formula V, R₃₅-R₃₈ can be independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl, hydroxyl, alkoxy, or aroxy.

In some forms of Formula V, J₁′ and J₂′ together can form a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, or a substituted or unsubstituted cycloalkynyl, such as an unsubstituted cycloalkyl, an unsubstituted cycloalkenyl, or an unsubstituted cycloalkynyl, for example, an unsubstituted cycloalkyl. The cycloalkyl, cycloalkenyl, and cycloalkynyl for Formula V can be monocyclic or polycyclic, such as a C₃-C₃₀, C₄-C₃₀, C₄-C₂₅, C₄-C₂₀, C₄-C₁₈, C₄-C₁₆, C₄-C₁₅, C₄-C₁₄, C₄-C₁₃, C₄-C₁₂, C₄-C₁₀, C₄-C₉, C₄-C₈, C₄-C₇, C₄-C₆, or C₄-C₅ monocyclic or polycyclic cycloalkyl, cycloalkenyl, or cycloalkynyl. For example, J₁′ and J₂′ together can form a monocyclic or polycyclic alkyl as shown below:

In some forms, the platinum (II) complex can contain one or two tetradentate ligands, each tetradentate ligand is in place of two bidentate bridging ligands. The inclusion of a tetradentate ligand in these platinum (II) complexes allows subtle structure refinement. For example, the replace of two bidentate bridging ligands with one tetradentate bridging ligand in these Pt(II) complexes narrows the full width at half maximum (FWHM) by about 30 nm in the emission profile, and retains the coordination mainframe and other photophysical properties, such as the shortened emission lifetime.

In some forms of Formulae I, I′, I″, Ia, Ia′, Ib, Ib′, II, II′, IIa, IIa′, IIb, IIb′, III, III′, III″, III′″, IIIa, IIa′, IIIb, IIb′, IV, IV′, IVa, IVa′, IVb, and/or IVb′, any one of the between R₅ and R₈, between R₆ and R₇, between R₅ and R₇, and between R₆ and R₈ can be absent, a single bond, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether. In some forms, at least one is not absent, such that the platinum (II) complex can contain one or two tetradentate ligands, each tetradentate ligand is in place of two bidentate bridging ligands. The inclusion of a tetradentate ligand in these platinum (II) complexes allows subtle structure refinement. For example, the replace of two bidentate bridging ligands with one tetradentate bridging ligand in these Pt(II) complexes narrows the full width at half maximum (FWHM) by about 30 nm in the emission profile, and retains the coordination mainframe and other photophysical properties, such as the shortened emission lifetime.

In some forms of Formulae I, I′, I″, Ia, Ia′, Ib, Ib′, II, II′, IIa, IIa′, IIb, IIb′, III, III′, III″, III′″, IIIa, IIIa′, IIIb, IIIb′, IV, IV′, IVa, IVa′, IVb, and/or IVb′, any one of

and can have a structure:

where: (a) A′ and B′ can be independently substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl, such as a substituted or unsubstituted aryl; and (b) each occurrence of L₅ can be independently ether, polyether, alkoxyl, thioether, sulfonyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, or substituted or unsubstituted alkynyl. In some forms, A′ and B′ can be independently substituted or unsubstituted aryl or substituted or unsubstituted polyaryl; and L₅ can have a structure:

where: (a) Q₁′ and Q₂′ can be independently absent, O or S; and (b) n9 can be an integer from 1 to 10, such as from 1 to 6, e.g. 1, 2, or 6.

In some forms of Formulae I, I′, I″, Ia, Ia′, Ib, Ib′, II, II′, IIa, IIa′, IIb, IIb′, III, III′, III″, III′″, IIIa, IIIa′, IIIb, IIIb′, IV, IV′, IVa, IVa′, IVb, and/or IVb′, the substituents for a substituted functional group can be a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a carbonyl, an alkoxy, an aroxy, an amino, an amido, or a hydroxyl, or a combination thereof.

In some forms of Formulae I, I′, I″, Ia, Ia′, Ib, Ib′, II, II′, IIa, IIa′, IIb, IIb′, III, III′, III″, III′″, IIIa, IIIa′, IIIb, IIIb′, IV, IV′, IVa, IVa′, IVb, and/or IVb′, the substituents for a substituted functional group can be an unsubstituted alkyl, an unsubstituted alkenyl, an unsubstituted alkynyl, an unsubstituted heterocyclyl, an unsubstituted aryl, an unsubstituted heteroaryl, an unsubstituted aralkyl, a carboxyl, an ester, a thioester, a hydroxyl, an alkoxy, an amino, or an amido, or a combination thereof.

In some forms of Formulae I, I′, I″, Ia, Ia′, Ib, Ib′, II, II′, IIa, IIa′, IIb, IIb′, III, III′, III″, III′″, IIIa, IIIa′, IIIb, IIIb′, IV, IV′, IVa, IVa′, IVb, and/or IVb′, the alkyl can be a linear alkyl, a branched alkyl, or a cyclic alkyl (either monocyclic or polycyclic). Exemplary alkyl include a linear C₁-C₃₀ alkyl, a branched C₄-C₃₀ alkyl, a cyclic C₃-C₃₀ alkyl, a linear C₁-C₂₀ alkyl, a branched C₄-C₂₀ alkyl, a cyclic C₃-C₂₀ alkyl, a linear C₁-C₁₀ alkyl, a branched C₄-C₁₀ alkyl, a cyclic C₃-C₁₀ alkyl, a linear C₁-C₆ alkyl, a branched C₄-C₆ alkyl, a cyclic C₃-C₆ alkyl, a linear C₁-C₄ alkyl, cyclic C₃-C₄ alkyl, such as a linear C₁-C₁₀, C₁-C₉, C₁-C₈, C₁-C₇, C₁-C₆, C₁-C₅, C₁-C₄, C₁-C₃, C₁-C₂ alkyl group, a branched C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ alkyl group, or a cyclic C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ alkyl group. The cyclic alkyl can be monocyclic alkyl or polycyclic alkyl, such as a C₃-C₃₀, C₄-C₃₀, C₄-C₂₅, C₄-C₂₀, C₄-C₁₈, C₄-C₁₆, C₄-C₁₅, C₄-C₁₄, C₄-C₁₃, C₄-C₁₂, C₄-C₁₀, C₄-C₉, C₄-C₈, C₄- C₇, C₄-C₆, or C₄-C₅ monocyclic or polycyclic alkyl group.

In some forms of Formulae I, I′, I″, Ia, Ia′, Ib, Ib′, II, II′, IIa, IIa′, IIb, IIb′, III, III′, III″, III′″, IIIa, IIa′, IIIb, IIIb′, IV, IV′, IVa, IVa′, IVb, and/or IVb′, the alkenyl can be a linear alkenyl, a branched alkenyl, or a cyclic alkenyl (either monocyclic or polycyclic). Exemplary alkenyl include a linear C₁-C₃₀ alkenyl, a branched C₄-C₃₀ alkenyl, a cyclic C₃-C₃₀ alkenyl, a linear C₁-C₂₀ alkenyl, a branched C₄-C₂₀ alkenyl, a cyclic C₃-C₂₀ alkenyl, a linear C₁-C₁₀ alkenyl, a branched C₄-C₁₀ alkenyl, a cyclic C₃-C₁₀ alkenyl, a linear C₁-C₆ alkenyl, a branched C₄-C₆ alkenyl, a cyclic C₃-C₆ alkenyl, a linear C₁-C₄ alkenyl, cyclic C₃-C₄ alkenyl, such as a linear C₁-C₁₀, C₁-C₉, C₁-C₈, C₁-C₇, C₁-C₆, C₁-C₅, C₁-C₄, C₁-C₃, C₁-C₂ alkenyl group, a branched C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ alkenyl group, or a cyclic C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ alkenyl group. The cyclic alkenyl can be monocyclic alkenyl or polycyclic alkenyl, such as a C₃-C₃₀, C₄-C₃₀, C₄-C₂₅, C₄-C₂₀, C₄-C₁₈, C₄-C₁₆, C₄-C₁₅, C₄-C₁₄, C₄-C₁₃, C₄-C₁₂, C₄-C₁₀, C₄-C₉, C₄-C₈, C₄-C₇, C₄-C₆, or C₄- C₅ monocyclic or polycyclic alkenyl group.

In some forms of Formulae I, I′, I″, Ia, Ia′, Ib, Ib′, II, II′, IIa, IIa′, IIb, IIb′, III, III′, III″, III′″, IIIa, IIIa′, IIIb, IIIb′, IV, IV′, IVa, IVa′, IVb, and/or IVb′, the alkynyl can be a linear alkynyl, a branched alkynyl, or a cyclic alkynyl (either monocyclic or polycyclic). Exemplary alkynyl include a linear C₁-C₃₀ alkynyl, a branched C₄-C₃₀ alkynyl, a cyclic C₃-C₃₀ alkynyl, a linear C₁-C₂₀ alkynyl, a branched C₄-C₂₀ alkynyl, a cyclic C₃-C₂₀ alkynyl, a linear C₁-C₁₀ alkynyl, a branched C₄-C₁₀ alkynyl, a cyclic C₃-C₁₀ alkynyl, a linear C₁-C₆ alkynyl, a branched C₄-C₆ alkynyl, a cyclic C₃-C₆ alkynyl, a linear C₁-C₄ alkynyl, cyclic C₃-C₄ alkynyl, such as a linear C₁-C₁₀, C₁-C₉, C₁-C₈, C₁-C₇, C₁-C₆, C₁-C₅, C₁-C₄, C₁-C₃, C₁-C₂ alkynyl group, a branched C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ alkynyl group, or a cyclic C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ alkynyl group. The cyclic alkynyl can be monocyclic or polycyclic alkynyl, such as a C₃-C₃₀, C₄-C₃₀, C₄-C₂₅, C₄-C₂₀, C₄-C₁₈, C₄-C₁₆, C₄-C₁₅, C₄-C₁₄, C₄-C₁₃, C₄-C₁₂, C₄-C₁₀, C₄-C₉, C₄-C₈, C₄-C₇, C₄-C₆, or C₄-C₅ monocyclic or polycyclic alkynyl group.

It is understood that any of the exemplary alkyl, alkenyl, and alkynyl groups can be heteroalkyl, heteroalkenyl, and heteroalkynyl, respectively. For example, the alkyl can be a linear C₂-C₃₀ heteroalkyl, a branched C₄-C₃₀ heteroalkyl, a cyclic C₃-C₃₀ heteroalkyl (i.e. a heterocycloalkyl), a linear C₁-C₂₀ heteroalkyl, a branched C₄-C₂₀ heteroalkyl, a cyclic C₃-C₂₀ heteroalkyl, a linear C₁-C₁₀ heteroalkyl, a branched C₄-C₁₀ heteroalkyl, a cyclic C₃-C₁₀ heteroalkyl, a linear C₁-C₆ heteroalkyl, a branched C₄-C₆ heteroalkyl, a cyclic C₃-C₆ heteroalkyl, a linear C₁-C₄ heteroalkyl, cyclic C₃-C₄ heteroalkyl, such as a linear C₁-C₁₀, C₁-C₉, C₁-C₈, C₁-C₇, C₁-C₆, C₁-C₅, C₁-C₄, C₁-C₃, C₁-C₂ heteroalkyl group, a branched C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ heteroalkyl group, or a cyclic C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ heteroalkyl group. The cyclic heteroalkyl can be monocyclic or polycyclic, such as a C₃-C₃₀, C₄-C₃₀, C₄-C₂₅, C₄-C₂₀, C₄-C₁₈, C₄-C₁₆, C₄-C₁₅, C₄-C₁₄, C₄-C₁₃, C₄-C₁₂, C₄-C₁₀, C₄-C₉, C₄-C₈, C₄-C₇, C₄-C₆, or C₄-C₅ monocyclic or polycyclic heteroalkyl group.

For example, the alkenyl can be a linear C₂-C₃₀ heteroalkenyl, a branched C₄-C₃₀ heteroalkenyl, a cyclic C₃-C₃₀ heteroalkenyl (i.e. a heterocycloalkenyl), a linear C₁-C₂₀ heteroalkenyl, a branched C₄-C₂₀ heteroalkenyl, a cyclic C₃-C₂₀ heteroalkenyl, a linear C₁-C₁₀ heteroalkenyl, a branched C₄-C₁₀ heteroalkenyl, a cyclic C₃-C₁₀ heteroalkenyl, a linear C₁-C₆ heteroalkenyl, a branched C₄-C₆ heteroalkenyl, a cyclic C₃-C₆ heteroalkenyl, a linear C₁-C₄ heteroalkenyl, cyclic C₃-C₄ heteroalkenyl, such as a linear C₁-C₁₀, C₁-C₉, C₁-C₈, C₁-C₇, C₁-C₆, C₁-C₅, C₁-C₄, C₁-C₃, C₁-C₂ heteroalkenyl group, a branched C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ heteroalkenyl group, or a cyclic C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ heteroalkenyl group. The cyclic heteroalkenyl can be monocyclic or polycyclic, such as a C₃-C₃₀, C₄-C₃₀, C₄-C₂₅, C₄-C₂₀, C₄-C₁₈, C₄-C₁₆, C₄-C₁₅, C₄-C₁₄, C₄-C₁₃, C₄-C₁₂, C₄-C₁₀, C₄-C₉, C₄-C₈, C₄-C₇, C₄-C₆, or C₄-C₅ monocyclic or polycyclic heteroalkenyl group.

For example, the alkynyl can be a linear C₂-C₃₀ heteroalkynyl, a branched C₄-C₃₀ heteroalkynyl, a cyclic C₃-C₃₀ heteroalkynyl (i.e. a heterocycloalkynyl), a linear C₁-C₂₀ heteroalkynyl, a branched C₄-C₂₀ heteroalkynyl, a cyclic C₃-C₂₀ heteroalkynyl, a linear C₁-C₁₀ heteroalkynyl, a branched C₄-C₁₀ heteroalkynyl, a cyclic C₃-C₁₀ heteroalkynyl, a linear C₁-C₆ heteroalkynyl, a branched C₄-C₆ heteroalkynyl, a cyclic C₃-C₆ heteroalkynyl, a linear C₁-C₄ heteroalkynyl, cyclic C₃-C₄ heteroalkynyl, such as a linear C₁-C₁₀, C₁-C₉, C₁-C₈, C₁-C₇, C₁-C₆, C₁-C₅, C₁-C₄, C₁-C₃, C₁-C₂ heteroalkynyl group, a branched C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ heteroalkynyl group, or a cyclic C₃-C₉, C₃-C₉, C₃-C₈, C₃-C₇, C₃-C₆, C₃-C₅, C₃-C₄ heteroalkynyl group. The cyclic heteroalkynyl can be monocyclic or polycyclic, such as a C₃-C₃₀, C₄-C₃₀, C₄-C₂₅, C₄-C₂₀, C₄-C₁₈, C₄-C₁₆, C₄-C₁₅, C₄-C₁₄, C₄-C₁₃, C₄-C₁₂, C₄-C₁₀, C₄-C₉, C₄-C₈, C₄-C₇, C₄-C₆, or C₄-C₅ monocyclic or polycyclic heteroalkynyl group.

For example, the aryl group can be a C₅-C₃₀ aryl, a C₅-C₂₀ aryl, a C₅-C₁₂ aryl, a C₅-C₁ aryl, a C₅-C₉ aryl, a C₆-C₂₀ aryl, a C₆-C₁₂ aryl, a C₆-C₁₁ aryl, or a C₆-C₉ aryl. It is understood that the aryl can be a heteroaryl, such as a C₅-C₃₀ heteroaryl, a C₅-C₂₀ heteroaryl, a C₅-C₁₂ heteroaryl, a C₅-C₁₁ heteroaryl, a C₅-C₉ heteroaryl, a C₆-C₃₀ heteroaryl, a C₆-C₂₀ heteroaryl, a C₆-C₁₂ heteroaryl, a C₆-C₁₁ heteroaryl, or a C₆-C₉ heteroaryl. The polyaryl group can be a C₁₀-C₃₀ polyaryl, a C₁₀-C₂₀ polyaryl, a C₁₀-C₁₂ polyaryl, a C₁₀-C₁₁ polyaryl, or a C₁₂-C₂₀ polyaryl. It is understood that the aryl can be a polyheteroaryl, such as a C₁₀-C₃₀ polyheteroaryl, a C₁₀-C₂₀ polyheteroaryl, a C₁₀-C₁₂ polyheteroaryl, a C₁₀-C₁₁ polyheteroaryl, or a C₁₂-C₂₀ polyheteroaryl.

The Pt(II) complexes may contain one or more chiral centers or may otherwise be capable of existing as multiple stereoisomers. These may be pure (single) stereoisomers or mixtures of stereoisomers, such as enantiomers, diastereomers, and enantiomerically or diastereomerically enriched mixtures. The Pt(II) complexes may be capable of existing as geometric isomers. Accordingly, it is to be understood that the present invention includes pure geometric isomers or mixtures of geometric isomers.

2. Exemplary Platinum(II) Complexes

Exemplary Pt(II) complexes are presented below.

3. Photophysical Properties

The photophysical properties of the Pt(II) complexes can be evaluated by emission lifetime (“τ_em” or “τ”), radiative decay rate (“k_r”), emission quantum yield (“QY” or “Ψ_em”), maximum emission wavelength (“λ_max”), and/or full width at half maximum (“FWHM”). Techniques for measuring the τ_em, k_r, QY, λ_max and FWHM of platinum (II) complexes are known. For example, these parameters can be obtained by measuring the emission spectra of a platinum (II) complex. For example, based on the measured emission spectra, the τ_em of the platinum (II) complex can be obtained as follows: (i) monitor the intensity of emission decay as a function of time using a Quanta Ray GCR 150-10 pulsed Nd:YAG laser system (pulse output: 355 nm), and (ii) determine the τ_em by fitting the exponential decay of formula (1) using Origin software, where I₀ is the initial emission intensity, I(t) is the emission intensity at time t, τ is the emission lifetime, and t is the time.

$\begin{array}{cc}I\left(t\right)=I_0{e}^{-t/\tau }& \mathrm{formula}\left(1\right)\end{array}$

The k_r of the platinum (II) complex can be obtained using k_r=Φ_em/τ_em. The Φ_em values of these Pt complexes can be measured by known methods, such as direct measurements or relative methods. For example, the Φ_em of the disclosed Pt(II) complexes in solutions or thin films, can be directly obtained by absolute measurement using Hamamatsu C11347 Quantaurus-QY Absolute PL quantum yield spectrometer (PL stands for photoluminescence). For example, the solution Φ_em of the disclosed Pt(II) complexes in the near infrared (“NIR”) region (i.e., λ_max in a range from 700 nm to about 1000 nm), such as complex 4a (λ_max=753_(max), 903 nm), can be measured by relative method using Pt(tpdbp) as standard reference Φ_r:0.51, λ_em=770 nm). In relative methods, Φ_em can be calculated by the equation: Φ_em=Φ_r (B_r/B_s) (n_s/n_r)² (D_s/D_r), where r and s represent sample and reference standard respectively, B=1-10^−AL, where A is the absorbance at excitation wavelength and L is the optical path length in cm, n is the refractive index of solvents, and D is the integrated emission intensity.

The λ_max and FWHM of the platinum (II) complex can be directly measured from the emission spectra.

In some forms, the platinum (II) complex of any one of Formulae I-IV can have an emission lifetime (τ_em) of up to 3.0 μs, up to 2.5 μs, up to 2.0 μs, in a range from 0.5 μs to 3.0 μs, from 0.8 μs to 3.0 μs, from 1.0 μs to 3.0 μs, from 0.5 μs to 2.5 μs, from 0.8 μs to 2.5 μs, from 1.0 μs to 2.5 μs, from 0.5 μs to 2.0 μs, from 0.8 μs to 2.0 μs, or from 1.0 μs to 2.0 μs, in solution or in films, such as obtained based on the emission spectra of the platinum (II) complex as described above.

In some forms, the platinum (II) complex of any one of Formulae I-IV can have a radiative decay rate (k_r) of at least 1.0×10⁵ s⁻¹, at least 1.4×10⁵ s⁻¹, in a range from 1.0×10⁵ s⁻¹ to 25.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 20.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 15.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 12.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 10.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 8.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 6.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 25.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 20.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 15.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 12.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 10.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 8.0×10⁵ s⁻¹, or from 1.4×10⁵ s⁻¹ to 6.0×10⁵ s⁻¹, in solution or in films, such as obtained based on the emission spectra of the platinum (II) complex as described above.

In some forms, the platinum (II) complex of any one of Formulae I-IV can have an emission quantum yield (“QY” or “Φ_em”) of at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, in a range from 50% to 90%, from 55% to 90%, from 60% to 90%, from 50% to 80%, from 55% to 80%, or from 60% to 80%, in solution or in films, at room temperature, such as obtained based on the emission spectra of the platinum (II) complex as described above.

In some forms, the platinum (II) complex of any one of Formulae I-IV can have a maximum emission wavelength (“λ_max”) in a range from 600 nm to 1000 nm, from 600 nm to 760 nm, from 600 nm to 735 nm, from 604 nm to 733 nm, from 600 nm to 700 nm, from 700 nm to 1000 nm, from 700 nm to 760 nm, or from 704 nm to 760 nm, such as obtained based on the emission spectra of the platinum (II) complex as described above. As used herein, near infrared (“Near-IR” or “NIR”) λ_max is in the range of 700 nm to 1000 nm, inclusive. As used herein, red λ_max is in the range of 600 nm to 700 nm, inclusive. A λ_max of exactly 700 nm can be considered either red or near infrared. However, in the context of a range of λ_max, whether 700 nm should be considered a near infrared λ_max or a red λ_max can be determined by whether 700 nm is the high endpoint or the low endpoint. In the context of a range of λ_max that spans below and above 700 nm, the range, and the 700 nm point, can be considered to encompass both red λ_max and near infrared λ_max.

In some forms, the platinum (II) complex of any one of Formulae I-IV can have a full width at half maximum (“FWHM”) of up to 270 nm, up to 250 nm, up to 220 nm, up to 200 nm, up to 180 nm, up to 160 nm, up to 145 nm, up to 135 nm, up to 120 nm, up to 110 nm, up to 100 nm, up to 90 nm, up to 80 nm, in a range from 50 nm to 270 nm, from 50 nm to 250 nm, from 50 nm to 220 nm, from 50 nm to 200 nm, from 50 nm to 180 nm, from 50 nm to 160 nm, from 50 nm to 145 nm, from 50 nm to 110 nm, from 60 nm to 270 nm, from 60 nm to 250 nm, from 60 nm to 220 nm, from 60 nm to 200 nm, from 60 nm to 145 nm, from 70 nm to 200 nm, or from 70 nm to 145 nm, such as obtained based on the emission spectra of the platinum (II) complex as described above. In some forms, the platinum (II) complex contains one or two tetradentate ligands having a full width at half maximum (“FWHM”) of up to 240 nm, up to 220 nm, up to 190 nm, up to 170 nm, up to 155 nm, up to 145 nm, up to 135 nm, up to 120 nm, up to 110 nm, up to 100 nm, up to 90 nm, up to 80 nm, in a range from 20 nm to 240 nm, from 20 nm to 220 nm, from 20 nm to 190 nm, from 20 nm to 170 nm, from 20 nm to 155 nm, from 20 nm to 145 nm, from 20 nm to 110 nm, from 20 nm to 100 nm, from 30 nm to 240 nm, from 30 nm to 220 nm, from 30 nm to 190 nm, from 30 nm to 170 nm, from 30 nm to 155 nm, from 30 nm to 145 nm, from 30 nm to 110 nm, from 40 nm to 240 nm, from 40 nm to 220 nm, from 40 nm to 190 nm, from 40 nm to 170 nm, from 40 nm to 155 nm, from 40 nm to 145 nm, from 40 nm to 115 nm, from 40 nm to 100 nm, from 50 nm to 115 nm, or from 50 nm to 100 nm, such as obtained based on the emission spectra of the platinum (II) complex as described above.

In some forms, the platinum (II) complex of any one of Formulae I-IV can have a τ_em, a k_r, a QY, a λ_max and/or a FWHM in any one of the above-described ranges. In some forms, the platinum (II) complex of any one of Formulae I-IV can have a τ_em of up to 3.0 μs, up to 2.5 μs, up to 2.0 μs, in a range from 0.5 μs to 3.0 μs, from 0.8 μs to 3.0 μs, from 1.0 μs to 3.0 μs, from 0.5 μs to 2.5 μs, from 0.8 μs to 2.5 μs, from 1.0 μs to 2.5 μs, from 0.5 μs to 2.0 μs, from 0.8 μs to 2.0 μs, or from 1.0 μs to 2.0 μs, in solution or in films; and a QY of at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, in a range from 50% to 90%, from 55% to 90%, from 60% to 90%, from 50% to 80%, from 55% to 80%, or from 60% to 80%, in solution or in films, at room temperature, such as obtained based on the emission spectra of the platinum (II) complex as described above. In some forms, the platinum (II) complex of any one of Formulae I-IV can have a τ_em of up to 3.0 μs, up to 2.5 μs, up to 2.0 μs, in a range from 0.5 μs to 3.0 μs, from 0.8 μs to 3.0 μs, from 1.0 μs to 3.0 μs, from 0.5 μs to 2.5 μs, from 0.8 μs to 2.5 μs, from 1.0 μs to 2.5 μs, from 0.5 μs to 2.0 μs, from 0.8 μs to 2.0 μs, or from 1.0 μs to 2.0 μs, in solution or in films; a k_r of at least 1.0×10⁵ s⁻¹, at least 1.4×10⁵ s⁻¹, in a range from 1.0×10⁵ s⁻¹ to 25.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 20.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 15.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 12.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 10.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 8.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 6.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 25.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 20.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 15.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 12.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 10.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 8.0×10⁵ s⁻¹, or from 1.4×10⁵ s⁻¹ to 6.0×10⁵ s⁻¹, in solution or in films; a QY of at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, in a range from 50% to 90%, from 55% to 90%, from 60% to 90%, from 50% to 80%, from 55% to 80%, or from 60% to 80%, in solution or in films, at room temperature; a λ_max in a range from 600 nm to 1000 nm, from 600 nm to 760 nm, from 600 nm to 735 nm, from 604 nm to 733 nm, from 600 nm to 700 nm, from 700 nm to 1000 nm, from 700 nm to 760 nm, or from 704 nm to 760 nm; and a FWHM of up to 270 nm, up to 250 nm, up to 220 nm, up to 200 nm, up to 180 nm, up to 160 nm, up to 145 nm, up to 135 nm, up to 120 nm, up to 110 nm, up to 100 nm, up to 90 nm, up to 80 nm, in a range from 50 nm to 270 nm, from 50 nm to 250 nm, from 50 nm to 220 nm, from 50 nm to 200 nm, from 50 nm to 180 nm, from 50 nm to 160 nm, from 50 nm to 145 nm, from 50 nm to 110 nm, from 60 nm to 270 nm, from 60 nm to 250 nm, from 60 nm to 220 nm, from 60 nm to 200 nm, from 60 nm to 145 nm, from 70 nm to 200 nm, or from 70 nm to 145 nm, such as obtained based on the emission spectra of the platinum (II) complex as described above.

Exemplary solutions suitable for measuring the τ_em, k_r, QY, λ_max and/or FWHM of the Pt(II) complexes include those that contain an organic solvent. Exemplary organic solvents suitable for use to form the measurement solutions include, but are not limited to, methylcyclopropane, dichloromethane and toluene, and a combination thereof. Optionally, the solutions for measuring the τ_em, k_r, QY, λ_max and/or FWHM of the Pt(II) complexes is degassed with an inert gas, such as nitrogen, argon, or helium, or a combination thereof. Suitable thin films for measuring the τ_em, k_r, QY, λ_max and/or FWHM of the Pt(II) complexes include films having a thickness between 10 nm and 5 μm, inclusive, or between 10 nm and 200 nm, inclusive. The films can also contain organic compounds as hot materials. Exemplary organic compounds that can be used as a host material in the films include, but are not limited to, 1,3-bis(N-carbazolyl)benzene (mCP), 3,3′-di(9H-carbazol-9-yl)-1,1′-biphenyl (mCBP), poly(methyl methacrylate) (PMMA), polystyrene (PS), 2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan (PPF), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO).

B. Devices Containing Platinum (II) Complexes

Organic light-emitting components, such as light-emitting diodes (OLEDs), containing one or more of the Pt(II) complexes are described. Other examples of organic light-emitting devices suitable for incorporation of the Pt(II) complexes disclosed herein include, but are not limited to, light-emitting electrochemical cells (LEECs). Devices containing one or more OLEDs containing one or more of the Pt(II) complexes include, but are not limited to, stationary visual display units, mobile visual display units, and illumination devices, such as smart phones, televisions, monitors, digital cameras, tablet computers, and lighting fixtures that usually operate at room temperatures, wearable devices, and medical monitoring devices.

In some forms, the Pt(II) complexes can be incorporated in a light-emitting layer. In some forms, the light-emitting layer can be incorporated in an organic light-emitting component, such as an OLED. Organic light-emitting components can contain one or more light-emitting layers, where each light-emitting layer can contain one or more the disclosed Pt(II) complexes. In some forms, the light-emitting layer or each light-emitting layer when two or more light-emitting layers are included in the organic light-emitting component further includes one or more host materials, such as those described above. Typically, the total concentration of the one or more host materials is greater than the total concentration of the one or more Pt(II) complexes in the light-emitting layer or each light-emitting layer of the two or more light-emitting layers. The term “total concentration of the one or more Pt(II) complexes” refers to the sum of the weight of the one or more Pt(II) complexes relative to the sum of the weights of all of the materials used in one light-emitting layer in an organic light-emitting device, such as an OLED. The term “total concentration of the one or more one or more host materials” refers to the sum of the weight of the one or more host materials relative to the sum of the weights of all of the materials used in one light-emitting layer in an organic light-emitting device, such as an OLED.

The organic light-emitting devices can contain a suitable amount of the Pt(II) complexes in the light-emitting layer or each light-emitting layer of the two or more light-emitting layers of the device. For example, the total concentration of the one or more Pt(II) complexes in the light-emitting layer or each light-emitting layer of the two or more light-emitting layers is up to 50 wt %, up to 40 wt %, up to 30 wt %, up to 20 wt %, at least 1 wt %, in a range from about 1 wt % to about 50 wt %, from about 1 wt % to about 40 wt %, from about 1 wt % to about 30 wt %, from about 1 wt % to about 20 wt %, from about 2 wt % to about 50 wt %, from about 2 wt % to about 40 wt %, from about 2 wt % to about 30 wt %, from about 2 wt % to about 20 wt %, from about 4 wt % to about 50 wt %, from about 4 wt % to about 40 wt %, from about 4 wt % to about 30 wt %, from about 4 wt % to about 20 wt %, from about 1 wt % to about 16 wt %, from about 2 wt % to about 16 wt %, from about 4 wt % to about 16 wt %, such as about 4 wt %, about 6 wt %, about 8 wt %, about 10 wt %, about 12 wt %, or about 16 wt %.

In some forms, the organic light-emitting component, such as an OLED, can further include an anode, a cathode, a hole transport region, and an electron transport region. The hole transport region can include a hole injection layer and/or a hole transport layer, and optionally an electron blocking layer. The electron transport region can include an electron transport layer and/or an electron injection layer, and optionally a hole blocking layer. The light-emitting layer can be located in between the anode and the cathodes. The hole transport region can be located in between the anode and the light-emitting layer. The electron transport region can be located in between the cathode and the light-emitting layer. The specific components and arrangement of the components in each of the hole transport region and the electron transport region depend on the specific use.

An exemplary OLED containing the Pt(II) complexes is illustrated in FIG. 13. As shown in FIG. 13, the exemplary OLED 100 includes multiple layers, which are, from bottom to top, a substrate 101, an anode 102, a hole injection layer 103, a hole transport layer 104, an optional electron blocking layer 105, an emission layer 106, an optional hole blocking layer 107, an electron transport layer 108, an electron injection layer 109, and a cathode 110. The emission layer 106 is formed by one or more of the Pt(II) complexes disclosed herein. Suitable materials for forming the anode, the hole injection layer, the hole transport layer, the optional electron blocking layer, the optional hole blocking layer, the electron transport layer, the electron injection layer, and the cathode are known in the art, see, for example, those described in Hong, et al., Adv. Mater. 2021, U.S. Pat. No. 2,005,630; Lee, et al., InfoMat. 2021, 3, 61-81; and Jou, et al., J. Mater. Chem. C, 2015, 3, 2974-3002. The dimensions of each layer in the OLED, such as the shape, the length, the width, and/or the thickness of each layer can be varied depending on the specific use of the OLED. More specific exemplary OLEDs are described in the Examples below.

These organic light-emitting devices can emit in the red to deep red regions with high efficiency and prolonged operational lifetime. Without being bound to any theories, the shortened emission lifetime of the Pt(II) complexes disclosed herein can reduce the efficiency roll-off and extend the operational lifetime of phosphorescent OLEDs. The stability gained from the dinuclearity of these Pt(II) complexes can extend the operational lifetime of red-emitting Pt-based OLEDs.

The performance of OLEDs containing the disclosed Pt(II) complexes can be evaluated using current efficiency (“CE”) at 1000 cd m⁻², power efficiency (“PE”) at 1000 cd m⁻², external quantum efficiency (“EQE”) at 1000 cd m⁻², and/or LT95 at 1000 cd m⁻². Techniques for measuring the current efficiency, power efficiency, external quantum efficiency, and/or LT95 at 1000 cd m⁻² are known. For example, the EQE, CE, and PE of an electroluminescence device can be obtained by using a Keithley 2400 source-meter and an absolute external quantum efficiency measurement system (C9920-12, Hamamatsu Photonics), where all devices can be encapsulated in a 200-nm-thick Al₂O₃ thin film deposited by atomic layer deposition (ALD) in a Kurt J. Lesker SPECTROS ALD system before measurements.

In some forms, OLEDs containing the disclosed Pt(II) complexes can have a current efficiency (“CE”) at 1000 cd m⁻² of at least 18 cd A-′, at least 20 cd/A, at least 25 cd/A, at least 30 cd/A, in a range from 18 cd/A to 60 cd/A, from 20 cd/A to 60 cd/A, from 25 cd/A to 60 cd/A, from 30 cd/A to 60 cd/A, from 18 cd/A to 50 cd/A, from 20 cd/A to 50 cd/A, from 25 cd/A to 50 cd/A, from 30 cd/A to 50 cd/A, from 18 cd/A to 40 cd/A, from 20 cd/A to 40 cd/A, from 25 cd/A to 40 cd/A, or from 30 cd/A to 40 cd/A.

In some forms, OLEDs containing the disclosed Pt(II) complexes can have a power efficiency (“PE”) at 1000 cd/m² of at least 6 lm/W, at least 10 lm/W, at least 15 lm/W, at least 20 lm/W, at least 25 lm/W, in a range from 6 lm/W to 60 lm/W, from 10 lm/W to 60 lm/W, from 15 lm/W to 60 lm/W, from 20 lm/W to 60 lm/W, from 6 lm/W to 50 lm/W, from 10 lm/W to 50 lm/W, from 15 lm/W to 50 lm/W, from 20 lm/W to 50 lm/W, from 6 lm/W to 40 lm/W, from 10 lm/W to 40 lm/W, from 15 lm/W to 40 lm/W, from 20 lm/W to 40 lm/W, from 6 lm/W to 35 lm/W, from 10 lm/W to 35 lm/W, from 15 lm/W to 35 lm/W, from 20 lm/W to 35 lm/W, from 6 lm/W to 30 lm/W, from 10 lm/W to 30 lm/W, from 15 lm/W to 30 lm/W, or from 20 lm/W to 30 lm/W.

In some forms, OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from about 600 nm to about 700 nm can have an external quantum efficiency (“EQE”) at 1000 cd m⁻² of at least 10%, at least 11%, at least 12%, at least 13%, at least 14%, at least 15%, in a range from 10% to 40%, from 10% to 20%, from 10% to 20%, from 11% to 40%, from 11% to 30%, from 11% to 20%, from 12% to 20%, from 12% to 40%, from 12% to 30%, from 13% to 20%, from 13% to 40%, from 13% to 30%, from 14% to 20%, from 14% to 40%, from 14% to 30%, from 15% to 40%, from 15% to 30%, or from 15% to 20% for an OLED containing a single light-emitting layer of the platinum (II) complexes. In some forms, OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from about 600 nm to about 700 nm can have an external quantum efficiency (“EQE”) at 1000 cd m⁻² of at least 20%, at least 30%, in a range from 20% to 60%, from 20% to 50%, from 20% to 40%, from 25% to 60%, from 25% to 50%, from 25% to 40%, from 30% to 60%, from 30% to 50%, from 30% to 40%, from 35% to 60%, from 35% to 50%, from 35% to 40%, from 40% to 60%, from 40% to 50%, or from 40% to 40% for an OLED containing three light-emitting layers of the platinum (II) complexes. In some forms, NIR OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from 700 nm to about 1000 nm can have an external quantum efficiency (“EQE”) at 100 mA cm⁻² of at least 2.5%, at least 4%, at least 5%, at least 6%, in a range from 2.5% to 20%, from 4% to 20%, from 5% to 20%, or from 6% to 20%.

In some forms, OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from about 600 nm to about 700 nm can have a LT95 at 1000 cd/m² of at least 9000 h, at least 9300 h, or at least 9500 h, such as at least 9000 h, at least 9300 h, or at least 9500 h. In some forms, NIR OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from 700 nm to about 1000 nm can have a LT95 at 1000 cd/m² of at least 1000 h, at least 1200 h, at least 1500 h, at least 2000 h, at least 2500 h, at least 3000 h, at least 3500 h, at least 4000 h, at least 4500 h, at least 5000 h, at least 5500 h, at least 6000 h, at least 6500 h, at least 7000 h, at least 7500 h, at least 8000 h, at least 8500 h, 9000 h, at least 9300 h, or at least 9500 h, such as at least 1000 h, at least 1200 h, at least 1500 h, or at least 2000 h.

In some forms, the OLEDs containing the disclosed Pt(II) complexes can have a current efficiency, a power efficiency, an external quantum efficiency, and/or a LT95 at 1000 cd m⁻² in any one of the above-described ranges. In some forms, the OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from about 600 nm to about 700 nm can have a CE at 1000 cd m⁻² of at least 18 cd A⁻¹, at least 20 cd/A, at least 25 cd/A, at least 30 cd/A, in a range from 18 cd/A to 60 cd/A, from 20 cd/A to 60 cd/A, from 25 cd/A to 60 cd/A, from 30 cd/A to 60 cd/A, from 18 cd/A to 50 cd/A, from 20 cd/A to 50 cd/A, from 25 cd/A to 50 cd/A, from 30 cd/A to 50 cd/A, from 18 cd/A to 40 cd/A, from 20 cd/A to 40 cd/A, from 25 cd/A to 40 cd/A, or from 30 cd/A to 40 cd/A; and a EQE at 1000 cd m⁻² of at least 10%, at least 11%, at least 12%, at least 13%, at least 14%, at least 15%, in a range from 10% to 40%, from 10% to 20%, from 10% to 20%, from 11% to 40%, from 11% to 30%, from 11% to 20%, from 12% to 20%, from 12% to 40%, from 12% to 30%, from 13% to 20%, from 13% to 40%, from 13% to 30%, from 14% to 20%, from 14% to 40%, from 14% to 30%, from 15% to 40%, from 15% to 30%, or from 15% to 20% (for a single light-emitting layer of the platinum (II) complexes).

In some forms, NIR OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from 700 nm to about 1000 nm can have a CE at 1000 cd m⁻² of at least 18 cd A-′, at least 20 cd/A, at least 25 cd/A, at least 30 cd/A, in a range from 18 cd/A to 60 cd/A, from 20 cd/A to 60 cd/A, from 25 cd/A to 60 cd/A, from 30 cd/A to 60 cd/A, from 18 cd/A to 50 cd/A, from 20 cd/A to 50 cd/A, from 25 cd/A to 50 cd/A, from 30 cd/A to 50 cd/A, from 18 cd/A to 40 cd/A, from 20 cd/A to 40 cd/A, from 25 cd/A to 40 cd/A, or from 30 cd/A to 40 cd/A; and a EQE at 100 mA cm⁻² of at least 2.5%, at least 4%, at least 5%, at least 6%, in a range from 2.5% to 20%, from 4% to 20%, from 5% to 20%, or from 6% to 20%.

In some forms, the OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from about 600 nm to about 700 nm can have a CE at 1000 cd m⁻² of at least 18 cd A⁻¹, at least 20 cd/A, at least 25 cd/A, at least 30 cd/A, in a range from 18 cd/A to 60 cd/A, from 20 cd/A to 60 cd/A, from 25 cd/A to 60 cd/A, from 30 cd/A to 60 cd/A, from 18 cd/A to 50 cd/A, from 20 cd/A to 50 cd/A, from 25 cd/A to 50 cd/A, from 30 cd/A to 50 cd/A, from 18 cd/A to 40 cd/A, from 20 cd/A to 40 cd/A, from 25 cd/A to 40 cd/A, or from 30 cd/A to 40 cd/A; a PE at 1000 cd/m² of at least 6 lm/W, at least 10 lm/W, at least 15 lm/W, at least 20 lm/W, at least 25 lm/W, in a range from 6 lm/W to 60 lm/W, from 10 lm/W to 60 lm/W, from 15 lm/W to 60 lm/W, from 20 lm/W to 60 lm/W, from 6 lm/W to 50 lm/W, from 10 lm/W to 50 lm/W, from 15 lm/W to 50 lm/W, from 20 lm/W to 50 lm/W, from 6 lm/W to 40 lm/W, from 10 lm/W to 40 lm/W, from 15 lm/W to 40 lm/W, from 20 lm/W to 40 lm/W, from 6 lm/W to 35 lm/W, from 10 lm/W to 35 lm/W, from 15 lm/W to 35 lm/W, from 20 lm/W to 35 lm/W, from 6 lm/W to 30 lm/W, from 10 lm/W to 30 lm/W, from 15 lm/W to 30 lm/W, or from 20 lm/W to 30 lm/W; a EQE at 1000 cd m⁻² of at least 10%, at least 11%, at least 12%, at least 13%, at least 14%, at least 15%, in a range from 10% to 40%, from 10% to 20%, from 10% to 20%, from 11% to 40%, from 11% to 30%, from 11% to 20%, from 12% to 20%, from 12% to 40%, from 12% to 30%, from 13% to 20%, from 13% to 40%, from 13% to 30%, from 14% to 20%, from 14% to 40%, from 14% to 30%, from 15% to 40%, from 15% to 30%, or from 15% to 20% (for a single light-emitting layer of the platinum (II) complexes); and a LT95 at 1000 cd/m² of at least 9000 h, at least 9300 h, or at least 9500 h.

In some forms, NIR OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from 700 nm to about 1000 nm can have a CE at 1000 cd m⁻² of at least 18 cd A-′, at least 20 cd/A, at least 25 cd/A, at least 30 cd/A, in a range from 18 cd/A to 60 cd/A, from 20 cd/A to 60 cd/A, from 25 cd/A to 60 cd/A, from 30 cd/A to 60 cd/A, from 18 cd/A to 50 cd/A, from 20 cd/A to 50 cd/A, from 25 cd/A to 50 cd/A, from 30 cd/A to 50 cd/A, from 18 cd/A to 40 cd/A, from 20 cd/A to 40 cd/A, from 25 cd/A to 40 cd/A, or from 30 cd/A to 40 cd/A; a PE at 1000 cd/m² of at least 6 lm/W, at least 10 lm/W, at least 15 lm/W, at least 20 lm/W, at least 25 lm/W, in a range from 6 lm/W to 60 lm/W, from 10 lm/W to 60 lm/W, from 15 lm/W to 60 lm/W, from 20 lm/W to 60 lm/W, from 6 lm/W to 50 lm/W, from 10 lm/W to 50 lm/W, from 15 lm/W to 50 lm/W, from 20 lm/W to 50 lm/W, from 6 lm/W to 40 lm/W, from 10 lm/W to 40 lm/W, from 15 lm/W to 40 lm/W, from 20 lm/W to 40 lm/W, from 6 lm/W to 35 lm/W, from 10 lm/W to 35 lm/W, from 15 lm/W to 35 lm/W, from 20 lm/W to 35 lm/W, from 6 lm/W to 30 lm/W, from 10 lm/W to 30 lm/W, from 15 lm/W to 30 lm/W, or from 20 lm/W to 30 lm/W; a EQE at 100 mA cm⁻² of at least 2.5%, at least 4%, at least 5%, at least 6%, in a range from 2.5% to 20%, from 4% to 20%, from 5% to 20%, or from 6% to 20%; and a LT95 at 1000 cd/m² of at least 1000 h, at least 1200 h, at least 1500 h, at least 2000 h, at least 2500 h, or at least 3000 h.

In some forms, OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from about 600 nm to about 700 nm and at a concentration in a range from about 4 wt % to about 16 wt % or from about 6 wt % to about 16 wt %, such as about 4 wt % or about 8 wt %, can have a current efficiency, a power efficiency, an external quantum efficiency, and/or a LT95 at 1000 cd m⁻² in any one of the above-described ranges. In some forms, the OLEDs containing the disclosed Pt(II) complexes at a concentration in a range from about 4 wt % to about 16 wt % or from about 6 wt % to about 16 wt %, such as about 4 wt % or about 8 wt %, can have a current efficiency at 1000 cd m⁻² of at least 24 cd/A, from 24 cd/A to 60 cd/A, from 24 cd/A to 50 cd/A, from 30 cd/A to 60 cd/A, from 30 cd/A to 50 cd/A, from 24 cd/A to 40 cd/A, or from 30 cd/A to 40 cd/A; and an external quantum efficiency at 1000 cd m⁻² of at least 10%, at least 11%, at least 12%, at least 13%, at least 14%, at least 15%, in a range from 10% to 40%, from 10% to 20%, from 10% to 20%, from 11% to 40%, from 11% to 30%, from 11% to 20%, from 12% to 20%, from 12% to 40%, from 12% to 30%, from 13% to 20%, from 13% to 40%, from 13% to 30%, from 14% to 20%, from 14% to 40%, from 14% to 30%, from 15% to 40%, from 15% to 30%, or from 15% to 20% (for a single light-emitting layer of the platinum (II) complexes).

In some forms, NIR OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from 700 nm to about 1000 nm and at a concentration in a range from about 4 wt % to about 16 wt % or from about 6 wt % to about 16 wt %, such as about 4 wt % or about 8 wt %, can have a current efficiency at 1000 cd m⁻² of at least 24 cd/A, from 24 cd/A to 60 cd/A, from 24 cd/A to 50 cd/A, from 30 cd/A to 60 cd/A, from 30 cd/A to 50 cd/A, from 24 cd/A to 40 cd/A, or from 30 cd/A to 40 cd/A; and an external quantum efficiency at 100 mA cm⁻² of at least 2.5%, at least 4%, at least 5%, at least 6%, in a range from 2.5% to 20%, from 4% to 20%, from 5% to 20%, or from 6% to 20%.

In some forms, the OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from about 600 nm to about 700 nm and at a concentration in a range from about 4 wt % to about 16 wt % or from about 6 wt % to about 16 wt %, such as about 4 wt % or about 8 wt %, can have a current efficiency at 1000 cd m⁻² of at least 24 cd/A, from 24 cd/A to 60 cd/A, from 24 cd/A to 50 cd/A, from 30 cd/A to 60 cd/A, from 30 cd/A to 50 cd/A, from 24 cd/A to 40 cd/A, or from 30 cd/A to 40 cd/A; a power efficiency at 1000 cd m⁻² of at least 10 lm/W, at least 15 lm/W, at least 20 lm/W, at least 25 lm/W, in a range from 10 lm/W to 60 lm/W, from 15 lm/W to 60 lm/W, from 20 lm/W to 60 lm/W, from 10 lm/W to 50 lm/W, from 15 lm/W to 50 lm/W, from 20 lm/W to 50 lm/W, from 10 lm/W to 40 lm/W, from 15 lm/W to 40 lm/W, from 20 lm/W to 40 lm/W, from 6 lm/W to 35 lm/W, from 10 lm/W to 35 lm/W, from 15 lm/W to 35 lm/W, or from 20 lm/W to 35 lm/W; an external quantum efficiency at 1000 cd m⁻² of at least 10%, at least 11%, at least 12%, at least 13%, at least 14%, at least 15%, in a range from 10% to 40%, from 10% to 20%, from 10% to 20%, from 11% to 40%, from 11% to 30%, from 11% to 20%, from 12% to 20%, from 12% to 40%, from 12% to 30%, from 13% to 20%, from 13% to 40%, from 13% to 30%, from 14% to 20%, from 14% to 40%, from 14% to 30%, from 15% to 40%, from 15% to 30%, or from 15% to 20% (for a single light-emitting layer of the platinum (II) complexes); and a LT95 at 1000 cd m⁻² of at least 9000 h or at least 9300 h.

In some forms, NIR OLEDs containing the disclosed Pt(II) complexes having λ_max in a range from 700 nm to about 1000 nm and at a concentration in a range from about 4 wt % to about 16 wt % or from about 6 wt % to about 16 wt %, such as about 4 wt % or about 8 wt %, can have a current efficiency at 1000 cd m⁻² of at least 24 cd/A, from 24 cd/A to 60 cd/A, from 24 cd/A to 50 cd/A, from 30 cd/A to 60 cd/A, from 30 cd/A to 50 cd/A, from 24 cd/A to 40 cd/A, or from 30 cd/A to 40 cd/A; a power efficiency at 1000 cd m⁻² of at least 10 lm/W, at least 15 lm/W, at least 20 lm/W, at least 25 lm/W, in a range from 10 lm/W to 60 lm/W, from 15 lm/W to 60 lm/W, from 20 lm/W to 60 lm/W, from 10 lm/W to 50 lm/W, from 15 lm/W to 50 lm/W, from 20 lm/W to 50 lm/W, from 10 lm/W to 40 lm/W, from 15 lm/W to 40 lm/W, from 20 lm/W to 40 lm/W, from 6 lm/W to 35 lm/W, from 10 lm/W to 35 lm/W, from 15 lm/W to 35 lm/W, or from 20 lm/W to 35 lm/W; an external quantum efficiency at 100 mA cm⁻² of at least 2.5%, at least 4%, at least 5%, at least 6%, in a range from 2.5% to 20%, from 4% to 20%, from 5% to 20%, or from 6% to 20%; and a LT95 at 1000 cd m⁻² of at least 1000 h or at least 1500 h.

More specific examples of the current efficiency, power efficiency, external quantum efficiency, and LT95 lifetime are described in the Examples.

III. Methods of Making the Platinum (II) Complexes

A. Pt(II) Complexes

The Pt(II) complexes and the ligands forming the Pt(II) complexes described herein can be synthesized using methods known in the art of organic chemical synthesis. The target Pt(II) complex can be synthesized by reacting a bidentate ligand and/or tetradentate ligand with a platinum precursor in a suitable solvent. Exemplary solvents include organic solvents, such as dimethylformamide. The reaction solution containing the bidentate ligand and/or tetradentate ligand and the platinum precursor can be refluxed for a suitable time to form the target Pt(II) complex. More specific reagents, reaction conditions, and Pt(II) complexes formed are described in the Examples.

B. Organic Light-Emitting Devices

Also described are methods of making organic light-emitting devices, such as OLEDs, containing one or more Pt(II) complexes disclosed herein. An exemplary method for making the OLEDs involves vacuum deposition or solution processing techniques such as spin-coating and ink-jet printing. A specific exemplary method of making an OLED containing a Pt(II) complex disclosed herein is disclosed in the Examples.

IV. Methods of Using the Platinum(II) Complexes

The Pt(II) complexes described herein can emit in the red and/or deep red regions at room temperatures with high quantum yield (such as >50%) and short emission lifetime (such as <3 μs). Accordingly, the Pt(II) complexes described herein can be incorporated into an organic light-emitting device to emit red and/or deep red light with high efficiency and prolonged operational lifetime, such as those described above.

For example, Pt(II) complexes described herein can be incorporated into an OLEDs, a light-emitting electrochemical cell (LEEC), a stationary visual display unit, a mobile visual display unit, or an illumination device. Examples of units or devices suitable for use as red/deep red light-emitting devices that incorporate the Pt(II) complexes disclosed herein include commercial applications such as smart phones, televisions, monitors, digital cameras, tablet computers, and lighting fixtures that usually operate at room temperatures.

The disclosed compounds, methods of using, and methods of making can be further understood through the following enumerated paragraphs.

Paragraph 1. A platinum (II) complex having a structure:

• • wherein:
  • (a) the compound has an overall neutral, negative, or positive charge;
  • (b) CY1, CY2, CY3, and CY4 are independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl;
  • (c) R₁, R₂, R₃, and R₄ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl;
  • (d) n1, n2, n3, and n4 are independently an integer between zero and 10;
  • (e) L₁ and L₃ are independently a single bond, a double bond, a triple bond, absent, oxygen, sulfur, amino, amido, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, carbonyl, sulfonyl, sulfonic acid, phosphoryl, or phosphonyl;
  • (f) R₅, R₆, R₇, and R₈ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy;
  • (g) L₂ and L₄ are independently a single bond, a double bond, a triple bond, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, amino, amido, or carbonyl; preferably, L₂ and L₄ are substituted or unsubstituted alkenyl;
  • (h) is absent, a single bond, a double bond, a triple bond, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; and
  • (i) the substituents are independently a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted alkoxy, a halogen, a hydroxyl, a phenoxy, an aroxy, an alkylthio, a phenylthio, an arylthio, a cyano, an isocyano, a nitro, an carboxyl, an amino, an amido, an oxo, a silyl, a sulfinyl, a sulfonyl, a sulfonic acid, a phosphonium, a phosphanyl, a phosphoryl, a phosphonyl, or a thiol, or a combination thereof.

Paragraph 2. The platinum (II) complex of paragraph 1, wherein the complex has a structure:

Paragraph 3. The platinum (II) complex of paragraph 1 or 2, having an overall neutral charge.

Paragraph 4. The platinum (II) complex of any one of paragraphs 1-3, wherein CY1, CY2, CY3, and CY4 are independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl.

Paragraph 5. The platinum (II) complex of any one of paragraphs 1-4 having a structure:

• • wherein:
  • (a) CY2 and CY3 are independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl;
  • (b) R₂ and R₃ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, oxo, amino, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol;
  • (c) n2, n3, n5, and n6 are independently an integer between zero and 10;
  • (d) R₅, R₆, R₇, and R₈ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl;
  • (e) R₉ and R₁₀ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol;
  • (f) R₁₁-R₁₄ and R₂₁-R₂₄ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol, and optionally R₁₁ and R₁₂ together, R₁₂ and R₁₃ together, R₁₃ and R₁₄ together, R₂₁ and R₂₂ together, R₂₂ and R₂₃ together, and/or R₂₃ and R₂₄ together form a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted cycloalkynyl, or a substituted or unsubstituted heterocyclyl;
  • (g) G1′ and G2′ are independently C or N;
  • (h) is absent, a single bond, a double bond, a triple bond, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether; and
  • (i) the substituents are independently a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted alkoxy, a halogen, a hydroxyl, a phenoxy, an aroxy, an alkylthio, a phenylthio, an arylthio, a cyano, an isocyano, a nitro, an carboxyl, an amino, an amido, an oxo, a silyl, a sulfinyl, a sulfonyl, a sulfonic acid, a phosphonium, a phosphanyl, a phosphoryl, a phosphonyl, or a thiol, or a combination thereof.

Paragraph 6. The platinum (II) complex of any one of paragraphs 1-5, CY2 and CY3 are independently substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl, and/or wherein n2 and n3 are independently an integer between 2 and 4, and two adjacent R₂ and/or two adjacent R₃ forms a substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, or substituted or unsubstituted cycloalkynyl.

Paragraph 7. The platinum (II) complex of any one of paragraphs 1-6 having a structure:

• • wherein:
  • (a) R₅, R₆, R₇, and R₈ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl;
  • (b) R₉ and R₁₀ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol;
  • (c) R₁₁-R₁₄ and R₂₁-R₂₄ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol, and optionally R₁₁ and R₁₂ together, R₁₂ and R₁₃ together, R₁₃ and R₁₄ together, R₂₁ and R₂₂ together, R₂₂ and R₂₃ together, and/or R₂₃ and R₂₄ together form a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted cycloalkynyl, or a substituted or unsubstituted heterocyclyl;
  • (d) each can be independently absent, a bond (single, double, or triple), a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether;
  • (e) X₁′, X₂′, Y₁′-Y₈′ can be independently O, S, CR₁₅, or NR₁₈, R₁₅ and R₁₈ can be independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; and
  • (f) the substituents are independently a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted alkoxy, a halogen, a hydroxyl, a phenoxy, an aroxy, an alkylthio, a phenylthio, an arylthio, a cyano, an isocyano, a nitro, an carboxyl, an amino, an amido, an oxo, a silyl, a sulfinyl, a sulfonyl, a sulfonic acid, a phosphonium, a phosphanyl, a phosphoryl, a phosphonyl, or a thiol, or a combination thereof.

Paragraph 8. The platinum (II) complex of any one of paragraphs 1-7 having a structure:

• • wherein:
  • (a) R₅, R₆, R₇, and R₈ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl;
  • (b) R₉ and R₁₀ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol;
  • (c) R₁₁-R₁₄, R₁₆, R₁₇, and R₁₉-R₂₄ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol, and optionally R₁₁ and R₁₂ together, R₁₂ and R₁₃ together, R₁₃ and R₁₄ together, R₁₆ and R₁₇ together, R₁₉ and R₂₀ together, R₂₁ and R₂₂ together, R₂₂ and R₂₃ together, and/or R₂₃ and R₂₄ together form a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted cycloalkynyl, or a substituted or unsubstituted heterocyclyl;
  • (d) is absent, a single bond, a double bond, a triple bond, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether;
  • (e) X₁′, X₂′, Y₁′, Y₂′, Y₃′, and Y₄′ are independently O, S, CR₁₅, or NR₁₈, R₁₅ and R₁₈ are independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; and
  • (f) the substituents are independently a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted alkoxy, a halogen, a hydroxyl, a phenoxy, an aroxy, an alkylthio, a phenylthio, an arylthio, a cyano, an isocyano, a nitro, an carboxyl, an amino, an amido, an oxo, a silyl, a sulfinyl, a sulfonyl, a sulfonic acid, a phosphonium, a phosphanyl, a phosphoryl, a phosphonyl, or a thiol, or a combination thereof.

Paragraph 9. The platinum (II) complex of paragraph 8, wherein X₁′, X₂′, Y₁′, Y₂′, Y₃′, and Y₄′ are independently CR₁₅ or NR₁₈, R₁₅ and R₁₈ are independently absent, hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl.

Paragraph 10. The platinum (II) complex of paragraph 8 or 9, wherein X₁′, X₂′, Y₁′ and/or Y₃′, and Y₂′ and/or Y₄′ are independently NR₁₈, each occurrence of R₁₈ is absent, hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl.

Paragraph 11. The platinum (II) complex of any one of paragraphs 8-10, wherein R₁₆, R₁₇, R₁₉, and R₂₀ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, or hydroxyl.

Paragraph 12. The platinum (II) complex of any one of paragraphs 1-7 having a structure:

• • wherein:
  • (a) R₅, R₆, R₇, and R₈ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, alkoxy, or aroxy; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl; preferably, R₅, R₆, R₇, and R₈ are independently substituted or unsubstituted aryl;
  • (b) R₉ and R₁₀ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; preferably, R₉ and R₁₀ are independently hydrogen, or substituted or unsubstituted alkyl; preferably, R₉ and R₁₀ independently hydrogen;
  • (c) R₁₁-R₁₄, R₂₁-R₂₄, and R₂₇-R₃₄ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, oxo, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol, and optionally Rn and R₁₂ together, R₁₂ and R₁₃ together, R₁₃ and R₁₄ together, R₂₁ and R₂₂ together, R₂₂ and R₂₃ together, R₂₃ and R₂₄, R₂₇ and R₂₈ together, R₂₈ and R₂₉ together, R₂₉ and R₃₀ together, R₃₁ and R₃₂ together, R₃₂ and R₃₃ together, and/or R₃₃ and R₃₄ together, form a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted cycloalkynyl, or a substituted or unsubstituted heterocyclyl;
  • (d) is absent, a single bond, a double bond, a triple bond, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, an alkoxy, an aroxy, an ether, a polyether, a sulfonyl, or a thioether;
  • (e) X₃′ and X₄′ are independently CR₂₅ or NR₂₆, R₂₅ and R₂₆ are independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol; and
  • (f) the substituents are independently a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted alkoxy, a halogen, a hydroxyl, a phenoxy, an aroxy, an alkylthio, a phenylthio, an arylthio, a cyano, an isocyano, a nitro, an carboxyl, an amino, an amido, an oxo, a silyl, a sulfinyl, a sulfonyl, a sulfonic acid, a phosphonium, a phosphanyl, a phosphoryl, a phosphonyl, or a thiol, or a combination thereof.

Paragraph 13. The platinum (II) complex of paragraph 12, wherein X₃′ and X₄′ are independently CR₂₅ or NR₂₆, R₂₅ and R₂₆ are independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl.

Paragraph 14. The platinum (II) complex of paragraph 12 or 13, wherein X₃′ and X₄′ are independently NR₂₆, each occurrence of R₂₆ is independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl.

Paragraph 15. The platinum (II) complex of any one of paragraphs 12-14, wherein R₂₇-R₃₄ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, or hydroxyl; Paragraph 16. The platinum (II) complex of any one of paragraphs 12-15, wherein R₂₇-R₃₄ are independently hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl.

Paragraph 17. The platinum (II) complex of any one of paragraphs 5-16 wherein R₉ and R₁₀ are independently hydrogen or substituted or unsubstituted alkyl.

Paragraph 18. The platinum (II) complex of any one of paragraphs 5-17, wherein R₁₁-R₁₄ and R₂₁-R₂₄ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, hydroxyl, alkoxy, or aroxy.

Paragraph 19. The platinum (II) complex of any one of paragraphs 5-18, wherein R₁₁, R₁₂, R₂₁, R₂₂ are hydrogen or R₁₁ and R₁₂ together forms a substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl and/or R₂₁ and R₂₂ together forms a substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl.

Paragraph 20. The platinum (II) complex of any one of paragraphs 5-19, wherein R₁₁, R₁₂, R₂₁, R₂₂ are hydrogen or R₁₁ and R₁₂ together forms and/or R₂₁ and R₂₂ together forms

• • wherein:
  • (a) Z′ is O, S, CR₃₉, or NR₄₀, R₃₉ and R₄₀ are independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol;
  • (b) J₁′ and J₂′ are independently

R₄₁ and R₄₂ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol, and optionally J₁′ and J₂′ together form a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, or a substituted or unsubstituted cycloalkynyl;

• • (c) n7 is an integer from 0 to 4; and
  • (d) R₃₅-R₃₈ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, halogen, hydroxyl, amino, azido, alkoxy, aroxy, cyano, isocyano, carbonyl, nitro, or thiol.

Paragraph 21. The platinum (II) complex of paragraph 20, wherein n7 and n8 are 0 and Z′ is O, S, or NR₄₀, each occurrence of R₄₀ is independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, or hydroxyl.

Paragraph 22. The platinum (II) complex of paragraph 20 or 21, wherein R₃₅-R₃₈ are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl, hydroxyl, alkoxy, or aroxy.

Paragraph 23. The platinum (II) complex of any one of paragraphs 1-22, wherein the between R₅ and R₈, between R₆ and R₇, between R₅ and R₇, and/or between R₆ and R₈ is absent or wherein

have a structure:

• • wherein:

• • (a) A′ and B′ are independently substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted aryl, substituted or unsubstituted polyaryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl; and
  • (b) each occurrence of L₅ is independently ether, polyether, alkoxyl, sulfonyl, thioether, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, or substituted or unsubstituted alkynyl.

Paragraph 24. The platinum (II) complex of paragraph 23, wherein A′ and B′ are independently substituted or unsubstituted aryl or substituted or unsubstituted polyaryl; and L₅ has a structure:

• • wherein:
  • (a) Q₁′ and Q₂′ are independently absent, O or S; and
  • (b) n9 is an integer from 1 to 10.

Paragraph 25. The platinum (II) complex of paragraph 1 having a structure:

Paragraph 26. The platinum (II) complex of any one of paragraphs 1-25 having an emission lifetime (τ_em) of up to 3.0 μs, up to 2.5 μs, up to 2.0 μs, in a range from 0.5 μs to 3.0 μs, from 0.8 μs to 3.0 μs, from 1.0 μs to 3.0 μs, from 0.5 μs to 2.5 μs, from 0.8 μs to 2.5 μs, from 1.0 μs to 2.5 μs, from 0.5 μs to 2.0 μs, from 0.8 μs to 2.0 μs, or from 1.0 μs to 2.0 μs, in solution or in films.

Paragraph 27. The platinum (II) complex of any one of paragraphs 1-26 having a radiative decay rate (k_r) of at least 1.0×10⁵ s⁻¹, at least 1.4×10⁵ s⁻¹, in a range from 1.0×10⁵ s⁻¹ to 25.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 20.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 15.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 12.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 10.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 8.0×10⁵ s⁻¹, from 1.0×10⁵ s⁻¹ to 6.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 25.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 20.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 15.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 12.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 10.0×10⁵ s⁻¹, from 1.4×10⁵ s⁻¹ to 8.0×10⁵ s⁻¹, or from 1.4×10⁵ s⁻¹ to 6.0×10⁵ s⁻¹, in solution or in films.

Paragraph 28. The platinum (II) complex of any one of paragraphs 1-27 having an emission quantum yield (“QY”) of at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, in a range from 50% to 90%, from 55% to 90%, from 60% to 90%, from 50% to 80%, from 55% to 80%, or from 60% to 80%, in solution or in films, at room temperature.

Paragraph 29. The platinum (II) complex of any one of paragraphs 1-28 having a maximum emission wavelength (“λ_max”) in a range from 600 nm to 760 nm, from 604 nm to 733 nm, from 600 nm to 700 nm, or from 700 nm to 1000 nm.

Paragraph 30. The platinum (II) complex of any one of paragraphs 1-29 having a full width at half maximum (“FWHM”) of up to 270 nm, up to 250 nm, up to 200 nm, up to 180 nm, up to 160 nm, up to 145 nm, up to 135 nm, up to 120 nm, up to 110 nm, up to 100 nm, up to 90 nm, up to 80 nm, in a range from 50 nm to 270 nm, from 50 nm to 250 nm, from 50 nm to 200 nm, from 50 nm to 180 nm, from 50 nm to 160 nm, from 50 nm to 145 nm, from 50 nm to 110 nm, from 60 nm to 145 nm, from 60 nm to 110 nm, from 70 nm to 145 nm, or from 70 nm to 110 nm.

Paragraph 31. An organic light-emitting component comprising a light-emitting layer or two or more light-emitting layers, wherein the light-emitting layer or each light-emitting layer of the two or more light-emitting layers comprises one or more platinum (II) complexes of any one of paragraphs 1 to 30.

Paragraph 32. The organic light-emitting component of paragraph 31, wherein the light emitting layer or each light-emitting layer of the two or more light-emitting layers further comprises one or more host materials, and wherein the total concentration of the one or more host materials is greater than the total concentration of the one or more complexes in the light-emitting layer or each light-emitting layer of the two or more light-emitting layers.

Paragraph 33. The organic light-emitting component of paragraph 32, wherein the total concentration of the one or more platinum (II) complexes in the light-emitting layer or each light-emitting layer of the two or more light-emitting layers is up to 50 wt %, up to 40 wt %, up to 30 wt %, up to 20 wt %, at least 1 wt %, in a range from about 1 wt % to about 50 wt %, from about 1 wt % to about 40 wt %, from about 1 wt % to about 30 wt %, from about 1 wt % to about 20 wt %, from about 2 wt % to about 50 wt %, from about 2 wt % to about 40 wt %, from about 2 wt % to about 30 wt %, from about 2 wt % to about 20 wt %, from about 4 wt % to about 50 wt %, from about 4 wt % to about 40 wt %, from about 4 wt % to about 30 wt %, from about 4 wt % to about 20 wt %, from about 1 wt % to about 16 wt %, from about 2 wt % to about 16 wt %, from about 4 wt % to about 16 wt %, such as about 4 wt %, about 6 wt %, about 8 wt %, about 10 wt %, about 12 wt %, or about 16 wt %.

Paragraph 34. The organic light-emitting component of any one of paragraphs 31-33 further comprising an anode, a cathode, a hole transport region, and an electron transport region,

• • wherein the hole transport region comprises a hole injection layer and/or a hole transport layer, and optionally an electron blocking layer,
  • wherein the electron transport region comprises an electron transport layer and/or an electron injection layer, and optionally a hole blocking layer,
  • wherein the light emitting layer is located in between the anode and the cathode,
  • wherein the hole transport region is located in between the anode and the light-emitting layer, and
  • wherein the electron transport region is located in between the cathode and the light emitting layer.

Paragraph 35. The organic light-emitting component of any one of paragraphs 31-34 having a current efficiency (“CE”) at 1000 cd/m² of at least 18 cd/A, at least 20 cd/A, at least 25 cd/A, at least 30 cd/A, in a range from 18 cd/A to 60 cd/A, from 20 cd/A to 60 cd/A, from 25 cd/A to 60 cd/A, from 30 cd/A to 60 cd/A, from 18 cd/A to 50 cd/A, from 20 cd/A to 50 cd/A, from 25 cd/A to 50 cd/A, from 30 cd/A to 50 cd/A, from 18 cd/A to 40 cd/A, from 20 cd/A to 40 cd/A, from 25 cd/A to 40 cd/A, or from 30 cd/A to 40 cd/A.

Paragraph 36. The organic light-emitting component of any one of paragraphs 31-35 having a power efficiency (“PE”) at 1000 cd/m² of at least 6 lm/W, at least 10 lm/W, at least 15 lm/W, at least 20 lm/W, at least 25 lm/W, in a range from 6 lm/W to 60 lm/W, from 10 lm/W to 60 lm/W, from 15 lm/W to 60 lm/W, from 20 lm/W to 60 lm/W, from 6 lm/W to 50 lm/W, from 10 lm/W to 50 lm/W, from 15 lm/W to 50 lm/W, from 20 lm/W to 50 lm/W, from 6 lm/W to 40 lm/W, from 10 lm/W to 40 lm/W, from 15 lm/W to 40 lm/W, from 20 lm/W to 40 lm/W, from 6 lm/W to 35 lm/W, from 10 lm/W to 35 lm/W, from 15 lm/W to 35 lm/W, from 20 lm/W to 35 lm/W, from 6 lm/W to 30 lm/W, from 10 lm/W to 30 lm/W, from 15 lm/W to 30 lm/W, or from 20 lm/W to 30 lm/W.

Paragraph 37. The organic light-emitting component of any one of paragraphs 31-36 having an external quantum efficiency (“EQE”) at 1000 cd m⁻² of at least 10%, at least 11%, at least 12%, at least 13%, at least 14%, at least 15%, in a range from 10% to 40%, from 10% to 20%, from 10% to 20%, from 11% to 40%, from 11% to 30%, from 11% to 20%, from 12% to 20%, from 12% to 40%, from 12% to 30%, from 13% to 20%, from 13% to 40%, from 13% to 30%, from 14% to 20%, from 14% to 40%, from 14% to 30%, from 15% to 40%, from 15% to 30%, or from 15% to 20% for a single layer of the platinum (II) complexes.

Paragraph 38. The organic light-emitting component of any one of paragraphs 31-37, wherein the one or more platinum (II) complexes have a λ_max in a range from 600 nm to 700 nm and the organic light-emitting component has a LT95 at 1000 cd/m² of at least 9000 h, at least 9300 h, or at least 9500 h, or wherein the one or more platinum (II) complexes have a λ_max in a range from 700 nm to 1000 nm and the organic light-emitting component has a LT95 at 1000 cd/m² of at least 1000 h, at least 1500 h, or at least 2000 h.

Paragraph 39. The organic light-emitting component of any one of paragraphs 31-38, wherein the organic light-emitting component is an organic light-emitting diode (“OLED”) or a light-emitting electrochemical cell (“LEEC”).

Paragraph 40. The organic light-emitting component of any one of paragraphs 31-39, wherein the light-emitting layer or each of the light-emitting layer of the two or more light-emitting layers is formed by vacuum-evaporation deposition, spin-coating, ink-printing, or roll-to-roll printing.

Paragraph 41. A device comprising one or more organic light-emitting components of any one of paragraphs 31-40, wherein the device is a stationary visual display unit, a mobile visual display unit, an illumination device, a wearable device, or a medical monitoring device.

The present invention will be further understood by reference to the following non-limiting examples.

EXAMPLES

Example 1. Synthesis of Exemplary Platinum (II) Complexes

Materials and Methods

Preparation of cyclometalating ligands L1 and L2

L1 and L2 were prepared according to the literature methods (Pinter, et al., Organometallics 2016, 35, 673-680; Pinter, et al., Chem. Eur. J. 2019, 25, 14495-14499).

Preparation of Bidentate and Tetradentate Bridging Ligands L3-L6

L3 was prepared according to the literature method (Hirano, et al., Org. Lett. 2009, 11, 1019-1022). To prepare S1 and S3, the corresponding nitrophenol (7.2 mmol), the corresponding Br(CH₂)_nBr (3.6 mmol) and K₂CO₃ (0.50 g, 3.6 mmol) were refluxed in DMF solution (20 ml) for 12 hours. After reaction, the mixture was cooled down to room temperature and iced water was poured into the reaction flask. The resulting precipitate was filtered, washed with water several times and dried in a 60° C. oven for 3 hrs to obtain the product.

To prepare S2 (n=1) or S4, the corresponding S1 or S3 (1.7 mmol), Pd/C 5% (0.028 g) and N₂H₄·H₂O (1.72 ml) were refluxed at absolute ethanol (6 ml) for 12 hours. After reaction, the mixture was cooled down to room temperature, and filtered through celite to remove Pd/C. The filtrate was evaporated and dissolved in DCM. The resulting solution was washed with water three times, followed by washing with brine and dried with Na₂SO₄. Solvent was evaporated under vacuum to obtain the product. S2 (n=2): 1,2-bis(2-aminophenoxy)ethane was received from BLDpharm chemical company and used directly.

To prepare L4, 1,2-bis(2-aminophenoxy)ethane (0.1 g, 0.41 mmol) and ethyl N-phenylformimidate (0.38 g, 2.6 mmol) were heated at 70° C. for 1 hour. The resulting sticky oil was triturated with hexane until it solidified. The resulting white solid was used directly without further purification. The preparation procedure for L5 is similar to L4, using 1,1-bis(2-aminophenoxy)methane instead of 1,2-bis(2-aminophenoxy)ethane. The preparation procedure for L6 is similar to L4, using 1,6-bis(3-aminophenoxy)hexane instead of 1,1-bis(2-aminophenoxy)ethane.

Preparation of Dinuclear Pt(II) Complexes

1a: To a solution of L1 (200 mg, 0.59 mmol) in dry DMF (10 ml) was added Ag₂O (76 mg, 0.32 mmol). The mixture was stirred overnight at room temperature in dark. Solvent was then removed under vacuum and Pt(COD)Cl₂ (221 mg, 0.59 mmol) was added to the reaction mixture. The resulting mixture was heated at 110° C. for 24 hours. After cooling to room temperature, to the mixture was added L3 (116 mg, 0.59 mmol) and potassium tert-butoxide (66 mg, 0.59 mmol) subsequently and heated at 100° C. for 18 hrs. After cooling to room temperature, the reaction mixture was filtered through a short pad of celite and the solvent was removed under vacuum. The resulting mixture was directed to a SiO₂ column and the product was isolated as orange solids with DCM/Hexane (v/v=1:2) as eluent.

1b: The mixture of [Pt(C{circumflex over ( )}C)(μ-Cl)]₂ (C{circumflex over ( )}C=1-methyl-3-phenyl-3H-imidazo[4,5-b]pyridin-1-ium-2-ylidene) (100 mg, 0.11 mmol), L4 (96 mg, 0.22 mmol) and K₂CO₃ (30 mg, 0.22 mmol) was refluxed in 1,2-dichloroethane (10 ml) under argon for 12 hours. After reaction, the solvent was removed under vacuum and the product was purified by column chromatography on SiO₂ with DCM/Hexane (v/v=3:1) as eluent.

1b′: It was isolated from the same pot of reaction yielding 1b. The product was purified by column chromatography on SiO₂ with DCM/Hexane (v/v=3:1) as eluent.

1c: The synthetic method for 1c is similar to that of 1b, using L5 instead of L4. The product was purified by column chromatography on SiO₂ with DCM/Hexane (v/v=3:1) as eluent.

1c′: It was isolated from the same pot of reaction yielding 1c. The product was purified by column chromatography on SiO₂ with DCM/Hexane (v/v=3:1) as eluent.

1d: The synthetic method for 1d is similar to that of 1b, using L6 instead of L4. The product was purified by column chromatography on SiO₂ with DCM/Hexane (v/v=3:1) as eluent.

1d′: It was isolated from the same pot of reaction yielding 1d. The product was purified by column chromatography on SiO₂ with DCM/Hexane (v/v=3:1) as eluent.

2a: The synthetic method for 2a is similar to that of 1a, using L2 instead of L1. The compound was isolated by collum chromatography with DCM/hexane (v/v=1:1) as eluent.

3a: The mixture of [Pt(2-phenylpyridine)Cl]₂ (100 mg, 0.13 mmol), L3 (59 mg, 0.3 mmol) and potassium tert-butoxide (34 mg, 0.3 mmol) was heated at 80° C. in DMF solution (9 ml) under argon overnight. After cooling to room temperature, DCM was added to the reaction mixture and the mixture was filtered through a short pad of celite. Solvent was then removed under vacuum and the product was isolated as deep red solid by column chromatography on SiO₂ with DCM/Hexane (v/v=1:3) as eluent.

3b: The synthetic method of 3b is similar to that of 3a, using L4 instead of L3.

4a: The synthetic method of 4a is similar to that of 3a, using [Pt(2-(dibenzo[b,d]furan-4-yl)pyridine)Cl]₂ instead of [Pt(2-phenylpyridine)Cl]₂.

2b: The synthetic method for 2b is similar to that of 2a, using L6 instead of L3. The compound was isolated by column chromatography with DCM/hexane (v/v=3:1) as eluent.

2b′: It was isolated from the same pot of reaction yielding 2b. The product was purified by column chromatography on SiO₂ with DCM/hexane (v/v=3:1) as eluent.

Results

S1 (n=1): Pale yellow solid, yield: 48%. ¹H NMR (400 MHz, CDCl₃) δ 7.85 (dd, J=8.1, 1.6 Hz, 2H), 7.63-7.56 (m, 2H), 7.51 (dd, J=8.4, 0.9 Hz, 2H), 7.22-7.14 (m, 2H), 5.93 (s, 2H). ¹³C NMR (101 MHz, CDCl₃) δ 149.63, 140.80, 134.52, 125.69, 123.14, 117.62, 91.88. HRMS(ESI-QTOF) m/z: cald. 313.0431; found 313.0437[(M⁺)].

S3 (n=6): Brown solid, yield: 50%. ¹H NMR (400 MHz, CDCl3) δ 7.81 (d, J=8.0 Hz, 2H), 7.72 (s, 2H), 7.42 (t, J=8.2 Hz, 2H), 7.22 (dd, J=8.2, 1.5 Hz, 2H), 4.06 (t, J=6.3 Hz, 4H), 1.97-1.78 (m, 4H), 1.58 (m, 4H). ¹³C NMR (101 MHz, CDCl3) δ 159.74, 149.35, 130.03, 121.80, 115.76, 108.78, 68.62, 29.07, 25.88. HRMS(ESI-QTOF) m/z: cald. 361.1394; found 361.1405[(M⁺)].

S2 (n=1): White crystallized solid, yield:0.68 g (86%). ¹H NMR (500 MHz, CDCl3) δ 7.10 (d, J=7.9 Hz, 2H), 6.88 (t, J=7.5 Hz, 2H), 6.72 (t, J=8.1 Hz, 4H), 5.74 (s, 2H), 3.58 (s, 6H). 13C NMR (126 MHz, CDCl3) δ 144.68, 137.48, 123.48, 118.69, 115.96, 115.58, 92.93. EI-MS (+ve, m/z): 230.1.

S4 (n=6): Off-white crystallized solid, yield: 80%. ¹H NMR (500 MHz, CDCl3) δ 7.04 (t, J=8.0 Hz, 2H), 6.31 (dd, J=8.2, 1.5 Hz, 2H), 6.26 (t, J=7.8 Hz, 2H), 6.24 (d, J=2.0 Hz, 2H), 3.92 (t, J=6.5 Hz, 4H), 3.63 (m, 4H), 1.89-1.69 (m, 4H), 1.56-1.40 (m, 4H). ¹³C NMR (101 MHz, CDCl3) δ 160.38, 147.85, 130.18, 107.89, 104.72, 101.80, 67.72, 29.35, 25.99. EI-MS (+ve, m/z): 300.2.

L4: white solid, yield: 95%. ¹H NMR (400 MHz, CDCl3) δ 8.12 (s, 2H), 7.25 (m, 5H), 7.07-6.89 (m, 13H), 4.35 (s, 4H). ¹³C NMR (101 MHz, CDCl3) δ 155.28, 129.51, 129.31, 129.21, 124.38, 123.48, 123.46, 123.31, 122.24, 121.55, 120.15, 119.04, 113.44, 66.96, 62.53. EI-MS (+ve, m/z): 450.2.

L5: white solid, yield: 90%. ¹H NMR (400 MHz, CDCl₃) δ 8.14 (s, 2H), 7.27 (m, 5H), 7.15-6.92 (m, 13H), 5.73 (s, 2H). ¹³C NMR (101 MHz, CDCl₃) δ 155.29, 129.56, 129.43, 129.39, 129.22, 124.07, 123.75, 123.62, 123.56, 121.56, 119.83, 62.54. HRMS(ESI-QTOF) m/z: cald. 437.1972; found 437.1976[(M⁺)].

L6: off-white solid, yield: 88%. ¹H NMR (400 MHz, CDCl₃) δ 8.22 (s, 2H), 7.28 (dd, J=14.6, 6.4 Hz, 4H), 7.18 (t, J=9.4 Hz, 3H), 7.09-6.99 (m, 7H), 6.61 (dd, J=17.0, 8.4 Hz, 5H), 3.88 (t, J=6.2 Hz, 4H), 1.76 (m, 4H), 1.58-1.45 (m, 4H). ¹³C NMR (101 MHz, CDCl₃) δ 160.21, 130.26, 129.57, 129.51, 123.59, 123.55, 119.42, 119.09, 110.58, 109.43, 106.42, 67.43, 28.67, 25.28. HRMS(ESI-QTOF) m/z: cald. 507.2755; found 507.2741 [(M⁺)].

1a: Orange solid, yield: 35 mg (49%). ¹H NMR (600 MHz, DMSO) δ (ppm) 8.45 (s, 2H), 8.15 (dd, J=4.9, 1.1 Hz, 2H), 7.69 (dd, J=8.1, 1.0 Hz, 2H), 7.67-7.63 (m, 2H), 7.50 (d, J=7.8 Hz, 4H), 7.45 (d, J=7.8 Hz, 4H), 7.24 (dd, J=8.1, 4.9 Hz, 2H), 7.17 (t, J=7.9 Hz, 4H), 7.10 (t, J=7.9 Hz, 4H), 6.91 (dt, J=18.9, 7.4 Hz, 6H), 6.43 (td, J=7.7, 1.0 Hz, 2H), 6.24 (td, J=7.4, 1.0 Hz, 2H), 3.22 (s, 6H). ¹³C NMR (151 MHz, DMSO) δ 167.80, 160.17, 152.08, 150.73, 146.08, 143.65, 143.31, 133.83, 130.84, 128.47, 128.19, 127.21, 123.40, 123.26, 122.99, 122.62, 122.55, 121.16, 118.75, 117.94, 112.63, 31.77. HRMS(ESI-QTOF) m/z: cald. 1197.2959; found 1197.2980 [(M⁺)].

1b: Orange solid, yield: 11%. ¹H NMR (500 MHz, CD₂Cl₂) δ 8.86 (s, 2H), 8.21 (d, J=7.5 Hz, 2H), 8.14 (t, J=3.1 Hz, 2H), 7.72 (d, J=7.4 Hz, 2H), 7.46 (d, J=7.8 Hz, 2H), 7.28 (d, J=7.9 Hz, 4H), 7.11 (d, J=3.1 Hz, 4H), 7.00-6.87 (m, 10H), 6.81 (dd, J=18.1, 8.9 Hz, 4H), 6.75 (t, J=7.2 Hz, 2H), 4.33 (d, J=7.2 Hz, 2H), 3.72 (d, J=7.3 Hz, 2H), 2.73 (s, 6H). HRMS(ESI-QTOF) m/z: cald. 1255.3014; found 1255.3027 [(M⁺)].

1b′: Orange solid, yield: 1.8%. ¹H NMR (500 MHz, CD₂Cl₂) δ 8.73 (s, 2H), 8.28 (ddd, J=9.4, 6.4, 1.3 Hz, 4H), 7.64 (d, J=6.9 Hz, 2H), 7.38 (dd, J=8.0, 1.1 Hz, 2H), 7.21 (d, J=7.8 Hz, 4H), 7.13 (dd, J=8.0, 4.9 Hz, 2H), 7.05-6.88 (m, 8H), 6.88-6.76 (m, 4H), 6.69 (d, J=6.5 Hz, 2H), 6.08 (t, J=7.0 Hz, 2H), 5.98 (t, J=7.4 Hz, 2H), 4.32 (d, J=7.3 Hz, 2H), 4.03 (s, 6H), 3.69 (d, J=7.2 Hz, 2H). ¹³C NMR (126 MHz, CD₂Cl₂) δ 168.73, 165.25, 153.59, 152.11, 146.69, 144.77, 143.79, 142.80, 134.08, 130.65, 128.62, 128.46, 128.27, 123.72, 123.53, 123.05, 122.29, 121.91, 120.88, 117.76, 117.65, 115.66, 113.29, 70.13, 32.91. HRMS(ESI-QTOF) m/z: cald. 1255.3014; found 1255.3008 [(M⁺)].

1c: orange solid, yield: 15 mg (11%). ¹H NMR (400 MHz, CD₂Cl₂) δ 8.87 (s, 2H), 8.32 (d, J=6.8 Hz, 2H), 7.94-7.80 (m, 4H), 7.61 (d, J=6.4 Hz, 2H), 7.44 (d, J=7.7 Hz, 4H), 7.16-6.88 (m, 18H), 6.84 (t, J=7.2 Hz, 2H), 5.53 (s, 2H), 2.26 (s, 6H). HRMS(ESI-QTOF) m/z: cald. 1240.2779; found 1240.2769 [(M⁺)].

1c′: orange solid, yield: 1.4%. ¹H NMR (500 MHz, CD₂Cl₂) δ 8.74 (s, 1H), 8.68 (s, 1H), 8.41-8.29 (m, 2H), 7.77 (d, J=6.5 Hz, 1H), 7.71 (d, J=6.7 Hz, 1H), 7.64-7.53 (m, 4H), 7.50 (d, J=6.9 Hz, 1H), 7.44 (d, J=7.7 Hz, 2H), 7.28 (ddd, J=12.8, 8.0, 1.3 Hz, 3H), 7.14 (ddd, J=12.5, 6.3, 3.9 Hz, 4H), 7.07 (t, J=7.9 Hz, 2H), 6.93-6.83 (m, 4H), 6.64 (ddt, J=23.0, 14.0, 7.1 Hz, 5H), 6.54 (dd, J=7.3, 6.2 Hz, 1H), 6.36 (t, J=7.1 Hz, 1H), 6.30 (t, J=7.1 Hz, 1H), 5.90 (d, J=7.1 Hz, 1H), 5.76 (d, J=7.0 Hz, 1H), 3.89 (s, 3H), 3.66 (s, 3H). ¹³C NMR (126 MHz, CD₂Cl₂) δ 169.19, 168.49, 164.49, 164.37, 153.34, 152.68, 151.42, 151.35, 147.16, 146.88, 145.15, 145.04, 144.83, 144.65, 144.17, 143.99, 136.55, 135.34, 131.71, 130.94, 128.96, 128.69, 128.41, 128.25, 127.71, 124.20, 123.74, 123.64, 123.61, 123.56, 123.36, 123.34, 123.19, 122.76, 122.75, 122.65, 122.44, 120.31, 119.49, 117.99, 117.88, 117.85, 112.89, 112.68, 98.97, 77.99, 33.85, 33.25. HRMS(ESI-QTOF) m/z: cald. 1240.2779; found 1240.2736 [(M⁺)].

1d: orange solid, yield: 2%. ¹H NMR (500 MHz, CD₂Cl₂) δ 8.59 (s, 2H), 7.92-7.83 (m, 4H), 7.75-7.70 (m, 2H), 7.54 (dd, J=11.9, 4.4 Hz, 6H), 7.18 (t, J=8.0 Hz, 2H), 7.14-7.03 (m, 10H), 6.96 (td, J=7.4, 1.2 Hz, 2H), 6.90 (t, J=7.3 Hz, 2H), 6.56 (dd, J=10.8, 2.0 Hz, 4H), 4.24-4.06 (m, 2H), 3.82 (td, J=9.2, 5.1 Hz, 2H), 2.26 (s, 6H), 1.83 (m, 2H), 1.69 (ddd, J=19.7, 10.9, 6.4 Hz, 4H), 1.60-1.54 (m, 2H). ¹³C NMR (126 MHz, CD₂Cl₂) δ 169.68, 161.23, 160.28, 153.16, 152.32, 147.47, 144.33, 144.19, 135.33, 132.40, 129.33, 128.58, 126.87, 124.91, 123.57, 123.31, 122.86, 119.32, 118.05, 117.98, 114.02, 109.29, 108.35, 67.90, 31.00, 28.53, 25.29. HRMS(ESI-QTOF) m/z: cald. 1310.3562; found 1310.3583 [(M⁺)].

1d′: orange solid, yield: 10%. ¹H NMR (500 MHz, CD₂Cl₂) δ 8.59 (s, 1H), 8.54 (s, 1H), 8.03 (t, J=4.5 Hz, 2H), 7.78 (m, 4H), 7.57-7.42 (m, 4H), 7.35-7.03 (m, 12H), 6.99 (t, J=7.3 Hz, 1H), 6.90 (t, J=7.2 Hz, 1H), 6.82 (t, J=7.3 Hz, 2H), 6.71-6.51 (m, 5H), 6.48 (d, J=6.4 Hz, 1H), 4.05-3.94 (m, 2H), 3.84 (dd, J=10.3, 6.5 Hz, 1H), 3.75 (dd, J=9.1, 5.3 Hz, 1H), 2.77 (s, 3H), 2.72 (s, 3H), 1.65 (dd, J=19.2, 15.3 Hz, 6H), 1.43 (s, 2H). ¹³C NMR (126 MHz, CD₂Cl₂) δ 169.60, 161.21, 161.11, 159.91, 159.84, 154.48, 152.96, 152.83, 151.37, 147.39, 147.24, 144.40, 144.39, 144.20, 144.18, 135.03, 135.02, 131.83, 129.56, 129.49, 128.82, 128.67, 127.37, 127.36, 124.29, 123.72, 123.41, 122.97, 122.72, 122.69, 117.99, 117.97, 117.94, 117.91, 114.17, 113.91, 113.84, 113.72, 113.37, 113.24, 107.86, 107.63, 67.48, 66.86, 31.67, 31.63, 27.91, 24.88, 24.73. HRMS(ESI-QTOF) m/z: cald. 1311.3640; found 1311.3682[(M⁺)].

2a: deep red solid, yield: 20%. ¹H NMR (500 MHz, CD₂Cl₂) δ (ppm) 8.37-8.25 (m, 2H), 8.24-8.18 (m, 2H), 7.91 (d, J=7.1 Hz, 2H), 7.64 (d, J=7.1 Hz, 6H), 7.57-7.44 (m, 6H), 7.29 (dd, J=15.6, 7.5 Hz, 6H), 7.13 (t, J=7.8 Hz, 4H), 7.05 (t, J=7.8 Hz, 4H), 6.93 (t, J=7.3 Hz, 3H), 6.84 (t, J=7.2 Hz, 3H), 6.73 (d, J=6.9 Hz, 2H), 6.38 (t, J=7.4 Hz, 2H), 5.87 (t, J=6.9 Hz, 2H). ¹³C NMR (126 MHz, CD₂Cl₂) δ (ppm) 171.95, 159.19, 150.53, 149.72, 146.39, 141.99, 139.11, 138.22, 137.77, 135.58, 135.15, 131.88, 129.40, 128.05, 128.00, 124.25, 123.49, 122.77, 122.71, 122.65, 121.99, 114.21. HRMS(ESI-QTOF) m/z: cald. 1323.3177; found 1323.3227 [(M⁺)].

3a: deep red solid, yield: 42 mg (30%). ¹HNMR (500 MHz, CD₂Cl₂) δ (ppm) 8.38 (s, 2H), 7.60 (d, J=7.8 Hz, 4H), 7.55 (d, J=5.4 Hz, 2H), 7.48 (d, J=7.8 Hz, 4H), 7.37-7.27 (m, 4H), 7.25 (t, J=7.8 Hz, 4H), 7.06 (dt, J=17.0, 7.5 Hz, 8H), 6.95 (dd, J=13.2, 7.0 Hz, 4H), 6.87 (dd, J=13.0, 6.9 Hz, 4H), 6.06 (t, J=6.2 Hz, 2H). ¹³C NMR (101 MHz, DMSO) δ (ppm) 165.98, 159.35, 151.12, 150.50, 149.90, 144.76, 144.53, 137.10, 132.27, 128.83, 128.42, 128.33, 123.86, 123.23, 123.15, 122.37, 121.75, 120.64, 117.70. HRMS(ESI-QTOF) m/z: cald. 1089.0129; found 1089.2523[(M⁺)].

3b: deep red solid, yield: 10%. ¹H NMR (500 MHz, CD₂Cl₂) δ (ppm) 8.86 (d, J=5.3 Hz, 1H), 8.51 (s, 1H), 8.02 (d, J=7.9 Hz, 1H), 7.43 (t, J=7.6 Hz, 1H), 7.28 (d, J=7.8 Hz, 2H), 7.03 (d, J=8.0 Hz, 1H), 7.01-6.88 (m, 7H), 6.88-6.78 (m, 2H), 6.58 (t, J=7.4 Hz, 1H), 6.39 (d, J=7.4 Hz, 1H), 6.28 (t, J=7.3 Hz, 1H), 4.30 (d, J=7.3 Hz, 1H), 3.68 (d, J=7.1 Hz, 1H).

4a: deep red solid, yield: 25%. ¹H NMR (500 MHz, CD₂Cl₂) δ (ppm) 8.44 (s, 2H), 8.01 (d, J=7.8 Hz, 2H), 7.92 (d, J=7.4 Hz, 2H), 7.72-7.56 (m, 8H), 7.54-7.39 (m, 10H), 7.36 (t, 2H), 7.30 (t, J=7.6 Hz, 4H), 7.09 (q, J=7.8 Hz, 6H), 6.91 (dt, J=23.4, 7.3 Hz, 4H), 5.58 (t, J=6.4 Hz, 2H). ¹³C NMR (126 MHz, CDCl₃) δ (ppm) 164.61, 160.44, 155.00, 152.80, 151.52, 150.75, 150.66, 145.85, 135.77, 129.27, 128.86, 128.61, 128.17, 127.91, 125.91, 124.76, 124.59, 123.95, 123.06, 122.99, 122.88, 121.61, 120.90, 120.23, 119.80, 111.39. HRMS(ESI-QTOF) m/z: cald. 1269.1723; found 1268.2657[(M⁺)].

2b: Deep red solid, yield: 0.5%. ¹H NMR (500 MHz, CD₂Cl₂) δ (ppm) 8.30 (s, 2H), 8.22 (s, 2H), 7.91 (d, J=7.4 Hz, 2H), 7.81 (d, J=7.9 Hz, 2H), 7.64 (m, 6H), 7.48 (d, J=8.0 Hz, 8H), 7.34 (s, 2H), 7.14 (t, J=7.5 Hz, 4H), 7.04 (t, J=7.8 Hz, 2H), 6.95 (t, J=7.0 Hz, 2H), 6.65 (d, J=7.2 Hz, 2H), 6.37 (d, J=7.5 Hz, 4H), 5.81 (s, 4H), 4.00 (s, 2H), 3.65 (t, J=7.8 Hz, 2H), 1.71 (m, 2H), 1.61 (m, 2H), 1.44 (m, 2H). ¹³C NMR (126 MHz, CD₂Cl₂) δ (ppm) 172.06, 159.71, 159.45, 151.69, 149.68, 146.34, 141.83, 139.12, 138.33, 137.69, 135.41, 135.12, 131.80, 129.32, 128.02, 127.98, 123.88, 122.81, 122.46, 122.12, 120.45, 114.25, 109.22, 106.60, 67.64, 29.08, 25.93. HRMS(ESI-QTOF) m/z: calcd: 1437.3859; found: 1437.3829 [(M+H)⁺].

2b′: Deep red solid, yield: 14%. ¹H NMR (500 MHz, CD₂Cl₂) δ (ppm) 8.31 (t, J=2.3 Hz, 2H), 8.21 (t, J=3.0 Hz, 2H), 7.94 (d, J=7.7 Hz, 1H), 7.91 (d, J=7.7 Hz, 1H), 7.85 (s, 2H), 7.70-7.43 (m, 10H), 7.34-7.21 (m, 4H), 7.12 (t, J=7.9 Hz, 3H), 7.03 (t, J=7.7 Hz, 2H), 6.97-6.66 (m, 7H), 6.51 (dd, J=8.2, 2.0 Hz, 1H), 6.47-6.28 (m, 4H), 5.87 (t, J=8.2 Hz, 3H), 4.22-4.12 (m, 1H), 4.09-3.99 (m, 1H), 3.86 (dd, J=8.3, 4.9 Hz, 1H), 3.80 (d, J=9.3 Hz, 1H), 1.83-1.62 (m, 5H), 1.54 (s, 2H), 1.45-1.35 (m, 1H). ¹³C NMR (126 MHz, CD₂Cl₂) δ (ppm) 172.09, 159.65, 159.33, 159.22, 159.15, 152.27, 151.28, 150.46, 149.75, 146.46, 146.39, 142.04, 139.10, 138.22, 137.75, 135.59, 135.13, 135.09, 132.00, 131.95, 129.43, 129.38, 128.92, 128.62, 128.03, 127.96, 124.29, 123.48, 122.79, 122.68, 122.60, 122.02, 115.78, 114.49, 114.21, 112.78, 111.99, 108.32, 106.59, 67.08, 66.52, 28.26, 27.44, 24.65, 24.16. HRMS(ESI-QTOF) m/z: calcd: 1437.3859; found: 1437.3823 [(M+H)⁺].

The structures of the synthesized Pt(II) complexes are shown below:

The X-ray crystal structures of Pt(II) complexes 1a, 1b, 1c, 2b′, 3a, and 3b and their Pt—Pt contacts are shown in FIGS. 1A-1D, respectively.

Example 2. The Platinum (II) Complexes Show High Emission Quantum Yield and Shortened Emission Lifetime

Materials and Methods

The emission spectra of Pt(II) complexes 1a, 1b, 1b′, 1c, 1c′, 1d, 1d′, 2a, 3a, 3b, and 4a were measure in poly(methyl methacrylate) (“PMMA”) and 1,3-bis(N-carbazolyl)benzene (“MCP”) films at room temperature respectively. The radiative decay rates k_r was calculated by Φ_em/τ_em. The τ_em of the platinum (II) complexes was obtained as follows: (i) monitor the intensity of emission decay as a function of time using a Quanta Ray GCR 150-10 pulsed Nd:YAG laser system (pulse output: 355 nm), and (ii) determine the τ_em by fitting the exponential decay of formula (1) using Origin software, where I₀ is the initial emission intensity, I(t) is the emission intensity at time t, τ is the emission lifetime, and t is the time.

$\begin{array}{cc}I\left(t\right)=I_0{e}^{-t/\tau }& \mathrm{formula}\left(1\right)\end{array}$

The Φ_em values of the Pt(II) complexes 1a, 1b, 1b′, 1c, 1c′, 1d, 1d′, 2a, 3a, 3b, in solutions or thin films, were directly obtained by absolute measurement using Hamamatsu C11347 Quantaurus-QY Absolute PL quantum yield spectrometer (PL stands for photoluminescence). The solution Φ_em value of the Pt(II) complex 4a in the NIR region (λ_max=753_(max), 903 nm), was measured by relative method using Pt(tpdbp) as standard reference (Φ_r:0.51, λ_em=770 nm). Φ_em was then calculated by the equation: Φ_em=Φ_r (B_r/B_s) (n_s/n_r)² (D_s/D_r), where r and s represent sample and reference standard respectively, B=1-10^−AL, where A is the absorbance at excitation wavelength and L is the optical path length in cm, n is the refractive index of solvents, and D is the integrated emission intensity.

Results

Photophysical Properties

The Pt(II) complexes 1a, 1b, 1b′, 1c, 1c′, 1d, 1d′, 2a, 2b, 2b′, 3a, 3b, and 4b display red to deep red emissions (λ_max=604-733 nm) in both solutions and thin films upon light excitation at room temperature (see FIGS. 2A-2H). The emission data of these Pt(II) complexes are summarized in Table 1 below. A high emission quantum yield of up to 0.8 (i.e. 80%) and a short lifetime down to 1.3 μs have been observed. The calculated radiative decay rates by k_r=Φ_em/τ_em, are all in the order of 10⁵ s⁻¹.

TABLE 1
Emission data of Pt(II) complexes at room temperature
			FWHM/	Φem;	kr;
	Medium	λem/nm	cm−1	τem/μs	knr/×105 s−1
1a	CH2Cl2	619	2241	0.62; 1.43	4.3; 2.7
	2 wt % in PMMA	604	2159	0.76; 1.62	4.7; 1.5
	2 wt % in MCP	604	2088	0.83; 1.25	6.6; 1.4
1b	CH2Cl2	632	2111	0.72; 1.90	3.3; 1.8
	2 wt % in PMMA	617	2127	0.47; 1.65	3.5; 2.5
	2 wt % in MCP	616	2037	0.43; 1.35	5.0; 2.4
1b′	CH2Cl2	630	2143	0.73; 2.02	3.6; 1.3
	2 wt % in PMMA	621	2018	0.74; 1.90	3.9; 1.4
	2 wt % in MCP	619	2011	0.67; 1.59	4.2; 2.1
1c	CH2Cl2	627	2247	0.76; 1.78	4.3; 1.3
	2 wt % in PMMA	613	2117	0.64; 1.49	4.3; 2.4
	2 wt % in MCP	604	2110	0.65; 1.30	5.0; 2.7
1c′	CH2Cl2	640	2081	0.73; 2.57	2.8; 1.1
	2 wt % in PMMA	628	2069	0.66; 1.90	3.5; 1.8
	2 wt % in MCP	634	2053	0.54; 1.88	2.9; 2.4
1d	CH2Cl2	617	2164	0.79; 1.68	4.7; 1.3
	2 wt % in PMMA	605	2098	0.74; 1.47	5.0; 1.8
	2 wt % in MCP	609	2105	0.69; 1.66	4.2; 1.9
1d′	CH2Cl2	619	2188	0.74; 1.81	4.1; 1.4
	2 wt % in PMMA	602	2173	0.74; 1.41	5.2; 1.8
	2 wt % in MCP	605	1875	0.67; 1.14	5.9; 2.9
2a	CH2Cl2	691	2163	0.62; 1.99	3.1; 1.9
	2 wt % in PMMA	675	2181	0.64; 1.68	3.8; 2.1
	2 wt % in MCP	679	1975	0.77; 1.46	5.3; 1.6
2b	CH2Cl2	689	2123	0.68; 1.89	3.6; 1.7
	2 wt % in PMMA	675	2131	0.72; 1.73	4.2; 1.6
2b′	CH2Cl2	689	2153	0.61; 2.39	2.6; 1.6
	2 wt % in PMMA	672	2092	0.82; 1.84	4.5; 0.98
3a	CH2Cl2	733(max),	2605	0.27; 0.84	3.2; 8.7
		899
	2 wt % in PMMA	662	2793	0.46; 1.62	2.8; 3.3
	2 wt % in MCP	678	2562	0.43; 1.41	3.0; 4.0
3b	CH2Cl2	698	2338	0.48; 1.34	3.6; 3.8
	2 wt % in PMMA	667	2610	0.36; 1.99	1.8; 3.2
	2 wt % in MCP	677	2574	0.26; 1.80	1.4; 4.1
4a	CH2Cl2	753(max),	3760	0.35; 0.81	4.3; 8.0
		903
	2 wt % in PMMA	693	2693	0.40; 1.57	2.6; 3.8
	2 wt % in MCP	701	2683	0.34; 0.86	4.0; 7.7

Example 3. OLEDs Containing the Platinum (II) Complexes Show High Emission Quantum Yield and Prolonged Lifetime

Materials and Methods

The fabrication process of vacuum-deposited OLEDs

OLEDs are formed by vacuum depositing the Pt(II) complexes in the form of a film. Specifically, indium-tin-oxide (ITO) coated glass with a sheet resistance of 10 Ω/sq was used as the anode substrate. Before film deposition, patterned ITO substrates were cleaned with detergent, rinsed in de-ionized water, acetone, and isopropanol, and then dried in an oven for 1 h in a cleanroom. The slides were then treated in an ultraviolet-ozone chamber for 5 min. The OLEDs were fabricated in a Kurt J. Lesker SPECTROS vacuum deposition system with a base pressure of 10⁻⁷ mbar. In the vacuum chamber, organic materials were thermally deposited in sequence at a rate of 0.5 Ås⁻¹. The doping process in the EMLs was realized using co-deposition technology. Afterward, LiF (1.2 nm) and Al (100 nm) were thermally deposited at rates of 0.02 and 0.2 nm s⁻¹, respectively. The film thicknesses were determined in situ with calibrated oscillating quartz-crystal sensors.

Results

The emission luminescence spectra and the performance characteristics of devices containing Pt(II) complexes 1a, 1b, 1d′, 2a, 4a, 1c, and 2b′ are shown in FIGS. 3A-3D, 4A-4D, 5A-5D, 6A-6B, 7A-7F, 8A-8D, 9A-9D, 14A-14B, and 15A-15D, respectively. The performance data of these devices is summarized in Tables 2-8, 15, and 16, respectively. The device lifetime measurement results of devices containing Pt(II) complexes 1a, 1d′, 2a, 1b, 1c, and 2b′ are shown in FIGS. 10-12 and 16-18, respectively and their lifetime measurement data is summarized in Tables 9-11, and 17-19, respectively. The performance of devices containing Pt(II) complexes 1a and 2a are compared with known red emitters in Table 12. The performance data of commercially available OLEDs from Merck, Sumitomo, DuPont, and UDC is summarized in Table 13. The performance data of red and deep red OLEDs reported by Universal Display is summarized in Table 14.

The vacuum deposited OLEDs based on 1a and 1b show red electroluminescence with CIE coordinates around (0.63, 0.37) and (0.64, 0.36), respectively. In both cases, there is no significant change in the EL maxima and the FWHM remains ˜80 nm, when increasing the dopant concentration from 6 wt % to 12 wt %. The external quantum efficiency of these devices has reached 18.7% for 1a and 15.1% for 1b, at a high luminance level of 1000 cd m⁻². In particular, the device lifetime measurement of devices based on 1a shows a high value of LT90˜150 hours with initial luminance (L₀) at 8000 cd m⁻².

Further, near-IR (“NIR”) OLEDs have been fabricated with 2a by vacuum deposition. The EL maximum has shifted from 688 to 706 nm, when increasing the thickness of electron transport layer (ETL) from 40 to 120 nm, while the FWHM have remained around 100 nm. The device shows a high EQE of up to 13% at a luminance level of 1000 cd m⁻². The NIR OLEDs based on 2a also shows a high value of LT90˜380 hours with initial luminance (L₀) at 2000 cd m⁻².

TABLE 2
Performance data of vapor-deposited devices (system I*) with 1a.
		CE	PE	EQE
	L	[cd A−1]	[lm W−1]	[%]
1a	[cd		at 1000		at 1000		at 1000	CIE	FWHM	λmax
conc.	m−2]	Max	cd m−2	Max	cd m−2	Max	cd m−2	[(x, y)]	[nm]	[nm]
6	74000	29.88	26.69	42.48	16.25	19.37	17.60	0.63,	78	620
wt %								0.37
8	75000	37.61	28.70	59.09	15.52	23.53	18.71	0.63,	79	620
wt %								0.37
10	65000	33.72	27.93	50.54	14.70	21.78	18.66	0.63,	79	620
wt %								0.37
12	66200	31.78	27.13	48.34	14.10	21.14	18.02	0.63,	79	620
wt %								0.37
*System I device structure: ITO/HAT-CN(5 nm)/TAPC(20 nm)/Tris-PCz (10 nm)/Tris-PCz:B4PYPPM:Pt-1a (30 nm)/B4PYPPM(50 nm)/Liq (1 nm)/Al (100 nm).

TABLE 3
Performance data of vapor-deposited devices (system II*) with 1a.
		CE	PE	EQE
	L	[cd A−1]	[lm W−1]	[%]
1a	[cd		at 1000		at 1000		at 1000	CIE	λmax
conc.	m−2]	Max	cd m−2	Max	cd m−2	Max	cd m−2	[(x, y)]	[nm]
4	58400	36.88	35.10	41.08	30.74	19.90	18.93	0.60,	612
wt %								0.40
8	63600	33.52	31.83	37.66	27.73	19.14	18.15	0.61,	614
wt %								0.39
12	68100	33.63	31.92	37.17	27.14	19.87	18.89	0.62,	618
wt %								0.38
16	68800	32.43	31.12	35.89	25.23	19.75	18.92	0.62,	620
wt %								0.38
*System II device structure: ITO/HAT-CN(5 nm)/TAPC(40 nm)/TCTA(10 nm)/TCTA:TPBi:Pt-1a/TPBi(10 nm)/TmPyPb(40 nm)/LiF(1.2 nm)/Al(100 nm).

TABLE 4
Performance data of vapor-deposited devices with 1b.
		CE	PE	EQE
	L	[cd A−1]	[lm W−1]	[%]
1b	[cd		at 1000		at 1000		at 1000	CIE	FWHM	λmax
conc.	m−2]	Max	cd m−2	Max	cd m−2	Max	cd m−2	[(x, y)]	[nm]	[nm]
4	48500	25.16	21.04	26.19	15.28	17.58	14.73	0.63,	78	623
wt %								0.37
12	55200	20.75	18.25	22.15	13.63	16.62	14.64	0.64,	79	626
wt %								0.36
16	52200	20.44	18.20	23.01	13.57	17.15	15.13	0.64,	80	627
wt %								0.36

TABLE 5
Performance data of vapor-deposited devices
with 1d′ at doping concentration of 4 wt %.
		CE	PE	EQE
	L	[cd A−1]	[lm W−1]	[%]
1d′	[cd		at 1000		at 1000		at 1000	CIE	FWHM	λmax
conc.	m−2]	Max	cd m−2	Max	cd m−2	Max	cd m−2	[(x, y)]	[nm]	[nm]
4	94000	31.5	30.1	32.3	19.9	20.6	19.6	0.63,	76	622
wt %								0.37

TABLE 6
Performance data of vapor-deposited devices with
2a at 6 wt % and various thickness of ETL.
	Thickness	Max.	EQE
	Of	Radiance	[%]
2a	ETL	flux		at 1000	FWHM	λmax
conc.	[nm]	[mW]	Max	cd m−2	[nm]	[nm]
6	40	4.21	15.68	10.83	96	688
wt %	80	4.20	16.94	11.14	97	698
	100	3.49	15.41	9.04	98	702
	120	2.39	11.51	6.10	100	706

TABLE 7
Performance data of vapor-deposited devices with
2a at doping concentration of 4 wt %-16 wt %.
Conc.		EQE [%]	λmax	CIE
(wt %)	L (cd m−2)	Max	at 1000 cd m−2	[nm]	(x, y)
4	13300	11.99	9.64	683	0.59, 0.38
8	12600	15.05	13.01	687	0.69, 0.30
12	10500	14.85	12.58	691	0.70, 0.30
16	10400	14.41	12.36	693	0.70, 0.30

TABLE 8
Performance data of vapor-deposited devices with
4a at 6 wt % and various thickness of ETL.
Thickness	Max.
of ETL	Radiance flux	EQE [%]	λmax
[nm]	[mW]	Max	at 100 mA cm−2	[nm]
40	3.19	10.12	6.22	704
80	2.11	8.92	5.35	724
100	1.39	6.76	4.15	732
120	1.07	4.67	2.59	759

TABLE 9
Lifetime measurement data for OLED containing 1a (the luminance
intensity at which LT is measured refers to L0).
	1a conc.	L0 (cd m−2)	LT97 (h)	LT90 (h)
	8 wt %	8500	23	134
	12 wt %	8100	21	152
	16 wt %	8030	20	158

TABLE 10
Lifetime measurement data for OLED containing 1d′ (the
luminance intensity at which LT is measured refers to L0).
	1d′ conc.	L0 (cd m−2)	LT97 (h)	LT95 (h)
	4 wt %	12000	35.2	90.6

TABLE 11
Lifetime measurement data for OLED containing
2a (the luminance intensity at which LT is measured
is at 2000 nits, referring to L0).
2a conc.	L0 (cd m−2)	LT97 (h)	LT95 (h)	LT90 (h)
4 wt %	2000	2.94	8.57	34.6
8 wt %	2000	19.5	54.1	202
12 wt %	2000	90.4	162	381
16 wt %	2000	83.4	153	368

TABLE 12
Performance of devices containing Pt(II) complexes 1a and 2a
in comparison with known red emitters, measured under the
same conditions (same temperature, pressure, using
the same measuring instrument and parameters, etc.).
	Phosphorescent	Fluorescent	Previous	Current data
	emitter's data#	dye's data#	dye data~
CIE (x,y)	~(0.64, 0.36)	(0.67, 0.33)	(0.58,	1a (System I:
			0.35)	0.63, 0.37);
				1a (System II:
				0.60, 0.40);
				2a NIR: 698 nm,
				ca. (0.70, 0.30)
Current	30	11	19.5	28.7; 35.1; NA
efficiency
@1000
cd/m2
(cd/A)
Power	NA	NA	20.0	15.5; 30.7;
efficiency				(max.
@1000				radiance:
cd/m2				4.2 mW)
(lm/W)
External	NA	NA	14.5	18.7; 18.9;
quantum				13.0
efficiency
@1000
cd/m2 (%)
LT	LT95:	LT50:	NA	LT95@1000nits
	50000 h	160000 h		for 1a: ca.
				9300 h?
Price	350-600b	100	NA	500-600*
(USD/g)
#Forrest et al., Nanophotonics 2021; 10(1): 31-40)
bIHS Markit2019
*Estimation in laboratory scale
?The device structure used for lifetime measurement for la may be different from system I and II. The value of 9300 h is estimated from the results of test conducted by the industrial partner at L0 of 5000 nits (LT95 ~600 h). By using n = 1.7 as acceleration factor in formula LT(L1) = LT(L0) × (L0/L1)1.7 (where L+ refers to initial luminance and Li refers to desired luminance), LT95 at 1000 nits =~ 600 × (5000/1000)?1.7 = ~9255.
~structure of the previous dye tested:

TABLE 13
Performance of commercially available OLEDs from Merck, Sumitomo,
DuPont, and UDC, reported by the manufacturer and measured
under the same conditions (same temperature, pressure, using
the same measuring instrument and parameters, etc.).
				UDC
Red	Merck	Sumitomo	DuPont	(Evaporable)
Efficiency (cd/A)	23	24	22	29
CIE (x, y)	0.65, 0.35	0.66, 0.34	0.65, 0.35	0.66, 0.34
LT95 at 1000 nits (hrs)	10,000	5,800	9,500	23,000

TABLE 14
Performance of red and deep red OLEDs reported by Universal
Display (web page oled-info.com/udc-pholed-material-performance-
update-green-now-reaches-14-million-hours).
PHOLED	1932 CIE	Luminous	Operating
performance	Color	Efficiency	Lifetime (hrs)
(at 1000 cd/m2)	Coordinates	(cd/A)	LT95	LT50
Deep Red	(0.69, 0.31)	17	14,000	250,000
Red	(0.66, 0.34)	24	25,000	600,000
Red	(0.64, 0.36)	30	50,000	900,000

TABLE 15
Performance data of vapor-deposited devices
with 1c at doping concentration of 4-16 wt %.
		CE	PE	EQE
	L	[cd A−1]	[lm W−1]	[%]
1c	[cd		at 1000		at 1000		at 1000	CIE	FWHM	λmax
conc.	m−2]	Max	cd m−2	Max	cd m−2	Max	cd m−2	[(x, y)]	[nm]	[nm]
4	34400	23.2	20.2	22.9	4.48	16.1	14.1	0.63,	82	624
wt %								0.37
8	41200	22.2	18.9	18.9	4.31	17.0	14.4	0.64,	83	627
wt %								0.36
16	46000	20.9	17.9	17.9	4.38	17.0	14.3	0.64,	85	632
wt %								0.36

TABLE 16
Performance data of vapor-deposited devices with
2b′ at doping concentration of 4-16 wt %.
		CE	PE	EQE
	L	[cd A−1]	[lm W−1]	[%]
2b′	[cd		at 1000		at 1000		at 1000	CIE	FWHM	λmax
conc.	m−2]	Max	cd m−2	Max	cd m−2	Max	cd m−2	[(x, y)]	[nm]	[nm]
4	9640	3.17	1.87	3.83	0.78	14.1	8.1	0.69,	96	686
wt %								0.31
8	10810	2.92	1.92	3.26	0.82	16.4	9.3	0.69,	96	689
wt %								0.31
16	11300	2.50	1.98	2.45	0.84	14.9	11.5	0.70,	99	692
wt %								0.30

TABLE 17
Lifetime measurement data for OLED containing 1b (the luminance
intensity at which LT is measured refers to L0)
	1b conc.	L0 (cd m−2)	LT97 (h)	LT95 (h)
	8 wt %	5000	2.9	6.2

TABLE 18
Lifetime measurement data for OLED containing 1c (the luminance
intensity at which LT is measured refers to L0)
	1c conc.	L0 (cd m−2)	LT97 (h)	LT95 (h)
	4 wt %	14400	4.3	17.5

TABLE 19
Lifetime measurement data for OLED containing 2b′ (the
luminance intensity at which LT is measured refers to L0)
	2b′ conc.	L0 (cd m−2)	LT97 (h)	LT95 (h)
	4 wt %	2600	54.5	125.2

Claims

1. A platinum (II) complex having a structure:

2. The platinum (II) complex of claim 1, wherein the complex has a structure:

3.-4. (canceled)

5. The platinum (II) complex of claim 1 having a structure:

6. (canceled)

7. The platinum (II) complex of claim 1 having a structure:

8. The platinum (II) complex of claim 1 having a structure:

9.-11. (canceled)

12. The platinum (II) complex of claim 1 having a structure:

13. The platinum (II) complex of claim 12, wherein X3′ and X4′ are independently CR25 or NR26, R25 and R26 are independently absent, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl.

14. (canceled)

15. The platinum (II) complex of claim 12, wherein R27-R34 are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, or hydroxyl.

16. (canceled)

17. The platinum (II) complex of claim 5 wherein R9 and R10 are independently hydrogen or substituted or unsubstituted alkyl.

18.-19. (canceled)

20. The platinum (II) complex of claim 5, wherein R11, R12, R21, R22 are hydrogen or R11 and R12 together forms and/or R21 and R22 together forms

21. The platinum (II) complex of claim 20, wherein n7 and n8 are 0 and Z′ is O, S, or NR40, each occurrence of R40 is independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, or hydroxyl.

22. The platinum (II) complex of claim 20, wherein R35-R38 are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted polyheteroaryl, or substituted or unsubstituted heterocyclyl, hydroxyl, alkoxy, or aroxy.

23. The platinum (II) complex of claim 1, wherein the between R5 and R8, between R6 and R7, between R5 and R7, and/or between R6 and R8 is absent or wherein

24. The platinum (II) complex of claim 23, wherein A′ and B′ are independently substituted or unsubstituted aryl or substituted or unsubstituted polyaryl; and L5 has a structure:

25. The platinum (II) complex of claim 1 having a structure:

26. The platinum (II) complex of claim 1 having: an emission lifetime (τem) of up to 3.0 μs, up to 2.5 μs, up to 2.0 μs, in a range from 0.5 μs to 3.0 μs, from 0.8 μs to 3.0 μs, from 1.0 μs to 3.0 μs, from 0.5 μs to 2.5 μs, from 0.8 μs to 2.5 μs, from 1.0 μs to 2.5 μs, from 0.5 μs to 2.0 μs, from 0.8 μs to 2.0 μs, or from 1.0 μs to 2.0 μs, in solution or in films, ora radiative decay rate (kr) of at least 1.0×105 s−1, at least 1.4×105 s−1, in a range from 1.0×105 s−1 to 25.0×105 s−1, from 1.0×105 s−1 to 20.0×105 s−1, from 1.0×105 s−1 to 15.0×105 s−1, from 1.0×105 s−1 to 12.0×105 s−1, from 1.0×105 s−1 to 10.0×105 s−1, from 1.0×105 s−1 to 8.0×105 s−1, from 1.0×105 s−1 to 6.0×105 s−1, from 1.4×105 s−1 to 25.0×105 s−1, from 1.4×105 s−1 to 20.0×105 s−1, from 1.4×105 s−1 to 15.0×105 s−1, from 1.4×105 s−1 to 12.0×105 s−1, from 1.4×105 s−1 to 10.0×105 s−1, from 1.4×105 s−1 to 8.0×105 s−1, or from 1.4×105 s−1 to 6.0×105 s−1, in solution or in films; oran emission quantum yield (“QY”) of at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, in a range from 50% to 90%, from 55% to 90%, from 60% to 90%, from 50% to 80%, from 55% to 80%, or from 60% to 80%, in solution or in films, at room temperature; ora maximum emission wavelength (“λmax”) in a range from 600 nm to 760 nm, from 604 nm to 733 nm, from 600 nm to 700 nm, or from 700 nm to 1000 nm; ora full width at half maximum (“FWHM”) of up to 270 nm, up to 250 nm, up to 200 nm, up to 180 nm, up to 160 nm, up to 145 nm, up to 135 nm, up to 120 nm, up to 110 nm, up to 100 nm, up to 90 nm, up to 80 nm, in a range from 50 nm to 270 nm, from 50 nm to 250 nm, from 50 nm to 200 nm, from 50 nm to 180 nm, from 50 nm to 160 nm, from 50 nm to 145 nm, from 50 nm to 110 nm, from 60 nm to 145 nm, from 60 nm to 110 nm, from 70 nm to 145 nm, or from 70 nm to 110 nm; ora combination thereof.

27-30. (canceled)

31. An organic light-emitting component comprising a light-emitting layer or two or more light-emitting layers, wherein the light-emitting layer or each light-emitting layer of the two or more light-emitting layers comprises one or more platinum (II) complexes of claim 1, optionally wherein the organic light-emitting component is an organic light-emitting diode (“OLED”) or a light-emitting electrochemical cell (“LEEC”).

32. The organic light-emitting component of claim 31, wherein the light emitting layer or each light-emitting layer of the two or more light-emitting layers further comprises one or more host materials, and wherein the total concentration of the one or more host materials is greater than the total concentration of the one or more complexes in the light-emitting layer or each light-emitting layer of the two or more light-emitting layers.

33. The organic light-emitting component of claim 32, wherein the total concentration of the one or more platinum (II) complexes in the light-emitting layer or each light-emitting layer of the two or more light-emitting layers is up to 50 wt %, up to 40 wt %, up to 30 wt %, up to 20 wt %, at least 1 wt %, in a range from about 1 wt % to about 50 wt %, from about 1 wt % to about 40 wt %, from about 1 wt % to about 30 wt %, from about 1 wt % to about 20 wt %, from about 2 wt % to about 50 wt %, from about 2 wt % to about 40 wt %, from about 2 wt % to about 30 wt %, from about 2 wt % to about 20 wt %, from about 4 wt % to about 50 wt %, from about 4 wt % to about 40 wt %, from about 4 wt % to about 30 wt %, from about 4 wt % to about 20 wt %, from about 1 wt % to about 16 wt %, from about 2 wt % to about 16 wt %, from about 4 wt % to about 16 wt %, such as about 4 wt %, about 6 wt %, about 8 wt %, about 10 wt %, about 12 wt %, or about 16 wt %.

34. The organic light-emitting component of claim 31 further comprising an anode, a cathode, a hole transport region, and an electron transport region, wherein the hole transport region comprises a hole injection layer and/or a hole transport layer, and optionally an electron blocking layer,wherein the electron transport region comprises an electron transport layer and/or an electron injection layer, and optionally a hole blocking layer,wherein the light emitting layer is located in between the anode and the cathode,wherein the hole transport region is located in between the anode and the light-emitting layer, andwherein the electron transport region is located in between the cathode and the light emitting layer.

35. The organic light-emitting component of claim 31 having a current efficiency (“CE”) at 1000 cd/m2 of at least 18 cd/A, at least 20 cd/A, at least 25 cd/A, at least 30 cd/A, in a range from 18 cd/A to 60 cd/A, from 20 cd/A to 60 cd/A, from 25 cd/A to 60 cd/A, from 30 cd/A to 60 cd/A, from 18 cd/A to 50 cd/A, from 20 cd/A to 50 cd/A, from 25 cd/A to 50 cd/A, from 30 cd/A to 50 cd/A, from 18 cd/A to 40 cd/A, from 20 cd/A to 40 cd/A, from 25 cd/A to 40 cd/A, or from 30 cd/A to 40 cd/A; or a power efficiency (“PE”) at 1000 cd/m2 of at least 6 lm/W, at least 10 lm/W, at least 15 lm/W, at least 20 lm/W, at least 25 lm/W, in a range from 6 lm/W to 60 lm/W, from 10 lm/W to 60 lm/W, from 15 lm/W to 60 lm/W, from 20 lm/W to 60 lm/W, from 6 lm/W to 50 lm/W, from 10 lm/W to 50 lm/W, from 15 lm/W to 50 lm/W, from 20 lm/W to 50 lm/W, from 6 lm/W to 40 lm/W, from 10 lm/W to 40 lm/W, from 15 lm/W to 40 lm/W, from 20 lm/W to 40 lm/W, from 6 lm/W to 35 lm/W, from 10 lm/W to 35 lm/W, from 15 lm/W to 35 lm/W, from 20 lm/W to 35 lm/W, from 6 lm/W to 30 lm/W, from 10 lm/W to 30 lm/W, from 15 lm/W to 30 lm/W, or from 20 lm/W to 30 lm/W: oran external quantum efficiency (“EQE”) at 1000 cd m−2 of at least 10%, at least 11%, at least 12%, at least 13%, at least 14%, at least 15%, in a range from 10% to 40%, from 10% to 20%, from 10% to 20%, from 11% to 40%, from 11% to 30%, from 11% to 20%, from 12% to 20%, from 12% to 40%, from 12% to 30%, from 13% to 20%, from 13% to 40%, from 13% to 30%, from 14% to 20%, from 14% to 40%, from 14% to 30%, from 15% to 40%, from 15% to 30%, or from 15% to 20% for a single layer of the platinum (II) complexes; ora LT95 at 1000 cd/m2 of at least 9000 h, at least 9300 h, or at least 9500 h, or wherein the one or more platinum (II) complexes have a λmax in a range from 700 nm to 1000 nm and the organic light-emitting component has a LT95 at 1000 cd/m2 of at least 1000 h, at least 1500 h, or at least 2000 h; ora combination thereof.

36-40. (canceled)

41. A device comprising one or more organic light-emitting components of claim 31, wherein the device is a stationary visual display unit, a mobile visual display unit, an illumination device, a wearable device, or a medical monitoring device.