Patent Application
20230276702
The object of the present invention is to provide molecules which are suitable for use in optoelectronic devices.
This object is achieved by the invention which provides a new class of organic molecules.
The organic molecules of the invention are purely organic molecules, i.e. they do not contain any metal ions in contrast to metal complexes known for use in optoelectronic devices.
The organic molecules exhibit emission maxima in the sky blue, green or yellow spectral range. The organic molecules exhibit in particular emission maxima between 490 and 600 nm, more preferably between 510 and 560 nm, and even more preferably between 520 and 540 nm. The photoluminescence quantum yields of the organic molecules according to the invention are, in particular, 10% or more. The molecules of the invention exhibit in particular thermally activated delayed fluorescence (TADF). The use of the molecules according to the invention in an optoelectronic device, for example, an organic light-emitting diode (OLED), leads to higher efficiencies of the device. Corresponding OLEDs have a higher stability than OLEDs with known emitter materials and comparable color and/or by employing the molecules according to the invention in an OLED display, a more accurate reproduction of visible colors in nature, i.e. a higher resolution in the displayed image, is achieved. In particular, the molecules can be used in combination with a fluorescence emitter to enable so-called hyper-fluorescence.
The organic molecules according to the invention include or consist of one first chemical moiety including or consisting of a structure of Formula I,
RA includes or consists at each occurrence, independently from each other of a structure of Formula BN-I,
R5 is at each occurrence independently from one another selected from the group consisting of: hydrogen, deuterium, N(R6)2, OR6, Si(R6)3, B(OR6)2, OSO2R6, CF3, CN, F, Br, I;
R6 is at each occurrence independently from one another selected from the group consisting of: hydrogen, deuterium, OPh (Ph=phenyl), CF3, CN, F;
Optionally, any of the substituents Ra, R3, R4 or R5 independently of each other form a mono- or polycyclic, aliphatic, aromatic and/or benzo-fused ring system with one or more other substituents Ra, R3, R4 or R5;
According to the invention, exactly one substituent selected from the group consisting of W, X, and Y is RA and exactly one substituent selected from the group consisting of T, V and W represents the binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties.
Moreover, exactly one substituent selected from the group consisting of W′, X′, and Y′ is RA and exactly one substituent selected from the group consisting of T′, V′ and W′ represents the binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties.
Furthermore, according to the invention, exactly one substituent selected from the group consisting of R11, R12, R13, R14, and R15 is RA.
In certain embodiments of the invention, T=T′, V=V′, W=W′, X=X′, Y=Y′ and the two second chemical moieties are identical.
In one embodiment of the invention, W and W′ are each a binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties.
In one embodiment of the invention, W and W′ are each a binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties, and X and X′ are RA.
In one embodiment of the invention, W and W′ are each a binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties, and Y and Y′ are RA.
In one embodiment of the invention, V and V′ are each a binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties.
In one embodiment of the invention, V and V′ are each a binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties, and W and W′ are RA.
In one embodiment of the invention, V and V′ are each a binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties, and X and X′ are RA.
In one embodiment of the invention, V and V′ are each a binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties, and Y and Y′ are RA.
In a preferred embodiment of the invention, T and T′ are each a binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties.
In a particularly preferred embodiment of the invention, T and T′ are each a binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties, and Wand W′ are RA.
In one embodiment of the invention, T and T′ are each a binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties, and X and X′ are RA.
In one embodiment of the invention, T and T′ are each a binding site of a single bond linking the first chemical moiety and one of the two second chemical moieties, and Y and Y′ are RA.
In one embodiment of the invention, RI is at each occurrence independently selected from the group consisting of H, methyl, mesityl, tolyl, and phenyl.
In another embodiment of the invention, RI is at each occurrence hydrogen.
In one embodiment of the invention, RA is at each occurrence represented by Formula BN-Ia.
In one embodiment of the invention, RA is at each occurrence represented by Formula BN-Ib.
In one embodiment of the invention, RA is at each occurrence represented by Formula BN-Ic.
In one embodiment of the invention, R3, R4, R5, and R6 are at each occurrence independently of each other selected from the group consisting of hydrogen, deuterium, halogen, CN, CF3, SiMe3, SiPh3;
In another embodiment of the invention, R3, R4, R5, and R6 are at each occurrence independently selected from the group consisting of hydrogen, deuterium, halogen, Me, iPr, tBu, CN, CF3, SiMe3, SiPh3, and
In another embodiment of the invention, R3, R4, R5, and R6 are at each occurrence independently selected from the group consisting of hydrogen, deuterium, halogen, Me, iPr, tBu, CN, CF3, SiMe3, SiPh3, and
In another embodiment of the invention, R3, R4, R5, and R6 are at each occurrence independently selected from the group consisting of hydrogen, deuterium, halogen, Me, iPr, tBu, CN, CF3, SiMe3, SiPh3, and
In one embodiment of the invention, the second chemical moiety includes or consists of a structure of Formula IIa:
In one embodiment of the invention, Ra is at each occurrence independently from one another selected from the group consisting of: hydrogen, Me, iPr, tBu, CN, CF3,
In a further embodiment of the invention, Ra is at each occurrence independently from one another selected from the group consisting of: hydrogen, Me, iPr, tBu, CN, CF3,
In a further embodiment of the invention, the second chemical moiety includes or consists of a structure of Formula IIb, a structure of Formula IIb-2, a structure of Formula IIb-3 or a structure of Formula IIb-4:
In an additional embodiment of the invention, the second chemical moiety includes or consists of a structure of Formula IIc, a structure of Formula IIc-2, a structure of Formula IIc-3 or a structure of Formula IIc-4:
In a further embodiment of the invention, Rb is at each occurrence independently from one another selected from the group consisting of: Me, iPr, tBu, CN, CF3,
In a further embodiment of the invention, Rb is at each occurrence independently from one another selected from the group consisting of: Me, iPr, tBu, CN, CF3,
Below, examples of the second chemical moiety are shown:
In one embodiment, Ra and R5 are at each occurrence independently from one another selected from the group consisting of hydrogen (H), methyl (Me), i-propyl (CH(CH3)2) (iPr), t-butyl (tBu), phenyl (Ph), CN, CF3, and diphenylamine (NPh2).
In one embodiment of the invention, the organic molecule includes or consists of a structure according to any selected from Formulas III, IV, V, VI, VII, VIII, IX, and X:
In another embodiment of the invention, the organic molecule includes or consists of a structure according to any selected from Formulas III, IV, V, VI, VII, VIII, IX, and X, wherein RI is at each occurrence hydrogen.
In a preferred embodiment of the invention, the organic molecule includes or consists of a structure according to Formula VIII.
In another preferred embodiment of the invention, the organic molecule includes or consists of a structure according to Formula VIII, wherein RI is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure according to Formula Villa, VIIIb, or VIlIc:
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula VIIIa, VIIIb, or VIIIc, wherein RI is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula VIIIa-1, VIIIb-1, or VIIIc-1:
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula VIIIa-1, VIIIb-1, or VIIIc-1, wherein RI is at each occurrence hydrogen.
In a preferred embodiment of the invention, the organic molecule includes or consists of a structure of Formula VIIIa-1 or VIIIb-1.
In another preferred embodiment of the invention, the organic molecule includes or consists of a structure of Formula VIIIa-1 or VIIIb-1, wherein RI is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula VIIIa-1a, VIIIa-1b, or VIIIa-1c:
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula VIIIa-1a, VIIIa-1b, or VIIIa-1c, wherein RI is at each occurrence hydrogen.
In a preferred embodiment of the invention, the organic molecule includes or consists of a structure of Formula VIIIa-1 b.
In another preferred embodiment of the invention, the organic molecule includes or consists of a structure according to Formula VIIIa-1 b, wherein RI is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure according to any selected from Formulas VIIIb-1a, VIIIb-1 b, and VIIIb-1c:
In one embodiment of the invention, the organic molecule includes or consists of a structure according to Formula VIIIb-1a, VIIIb-1 b, or VIIIb-1c, wherein RI is at each occurrence hydrogen.
In a preferred embodiment of the invention, the organic molecule includes or consists of a structure according to Formula VIIIb-1 b.
In another preferred embodiment of the invention, the organic molecule includes or consists of a structure according to Formula VIIIb-1 b, wherein RI is at each occurrence hydrogen.
In a particularly preferred embodiment of the invention, the organic molecule includes or consists of a structure according to any selected from Formulas VIIIa-1a-1, VIIIa-1b-1, VIIIb-1a-1, and VIIIb-1b-1:
In another preferred embodiment of the invention, the organic molecule includes or consists of a structure according to Formula VIIIa-1a-1, VIIIa-1b-1, VIIIb-1a-1, or VIIIb-1 b-1, wherein RI is at each occurrence hydrogen.
As used above and herein, the terms “aryl” and “aromatic” may be understood in the broadest sense as any mono-, bi- or polycyclic aromatic moieties. Accordingly, an aryl group contains 6 to 60 aromatic ring atoms, and a heteroaryl group contains 5 to 60 aromatic ring atoms, of which at least one is a heteroatom. Notwithstanding, throughout the application the number of aromatic ring atoms may be given as subscripted number in the definition of certain substituents. In particular, the heteroaromatic ring includes one to three heteroatoms. Again, the terms “heteroaryl” and “heteroaromatic” may be understood in the broadest sense as any mono-, bi- or polycyclic hetero-aromatic moieties that include at least one heteroatom. The heteroatoms may at each occurrence be the same or different and be individually selected from the group consisting of N, O and S. Accordingly, the term “arylene” refers to a divalent substituent that bears two binding sites to other molecular structures and thereby serving as a linker structure. In case, a group in the exemplary embodiments is defined differently from the definitions given here, for example, the number of aromatic ring atoms or number of heteroatoms differs from the given definition, the definition in the exemplary embodiments is to be applied. According to the invention, a condensed (annulated) aromatic or heteroaromatic polycycle is built of two or more single aromatic or heteroaromatic cycles, which formed the polycycle via a condensation reaction.
In particular, as used throughout the present application, examples of the term aryl group or heteroaryl group include groups which can be bound via any position of the aromatic or heteroaromatic group, derived from benzene, naphthalene, anthracene, phenanthrene, pyrene, dihydropyrene, chrysene, perylene, fluoranthene, benzanthracene, benzophenanthrene, tetracene, pentacene, benzopyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthoimidazole, phenanthroimidazole, pyridoimidazole, pyrazinoimidazole, quinoxalinoimidazole, oxazole, benzoxazole, naphthooxazole, anthroxazol, phenanthroxazol, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, 1,3,5-triazine, quinoxaline, pyrazine, phenazine, naphthyridine, carboline, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,2,3,4-tetrazine, purine, pteridine, indolizine and benzothiadiazole or combinations of the above mentioned groups.
As used throughout, the term cyclic group may be understood in the broadest sense as any mono-, bi- or polycyclic moieties.
As used above and herein, the term alkyl group may be understood in the broadest sense as any linear, branched, or cyclic alkyl substituent. In particular, examples of the term alkyl include the substituents methyl (Me), ethyl (Et), n-propyl (nPr), i-propyl (iPr), cyclopropyl, n-butyl (nBu), i-butyl (iBu), s-butyl (sBu), t-butyl (tBu), cyclobutyl, 2-methylbutyl, n-pentyl, s-pentyl, t-pentyl, 2-pentyl, neo-pentyl, cyclopentyl, n-hexyl, s-hexyl, t-hexyl, 2-hexyl, 3-hexyl, neo-hexyl, cyclohexyl, 1-methylcyclopentyl, 2-methylpentyl, n-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, cycloheptyl, 1-methylcyclohexyl, n-octyl, 2-ethylhexyl, cyclooctyl, 1-bicyclo[2,2,2]octyl, 2-bicyclo[2,2,2]-octyl, 2-(2,6-dimethyl)octyl, 3-(3,7-dimethyl)octyl, adamantyl, 2,2,2-trifluorethyl, 1,1-dimethyl-n-hex-1-yl, 1,1-dimethyl-n-hept-1-yl, 1,1-dimethyl-n-oct-1-yl, 1,1-dimethyl-n-dec-1-yl, 1,1-dimethyl-n-dodec-1-yl, 1,1-dimethyl-n-tetradec-1-yl, 1,1-dimethyl-n-hexadec-1-yl, 1,1-dimethyl-n-octadec-1-yl, 1,1-diethyl-n-hex-1-yl, 1,1-diethyl-n-hept-1-yl, 1,1-diethyl-n-oct-1-yl, 1,1-diethyl-n-dec-1-yl, 1,1-diethyl-n-dodec-1-yl, 1,1-diethyl-n-tetradec-1-yl, 1,1-diethyl-n-hexadec-1-yl, 1,1-diethyl-n-octadec-1-yl, 1-(n-propyl)-cyclohex-1-yl, 1-(n-butyl)-cyclohex-1-yl, 1-(n-hexyl)-cyclohex-1-yl, 1-(n-octyl)-cyclohex-1-yl and 1-(n-decyl)-cyclohex-1-yl.
As used above and herein, the term alkenyl includes linear, branched, and cyclic alkenyl substituents. The term alkenyl group, for example, includes the substituents ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl or cyclooctadienyl.
As used above and herein, examples of the term alkynyl include linear, branched, and cyclic alkynyl substituents. The term alkynyl group, for example, includes ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl.
As used above and herein, examples of the term alkoxy include linear, branched, and cyclic alkoxy substituents. Examples of the term alkoxy group, for example, include methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy and 2-methylbutoxy.
As used above and herein, the term thioalkoxy includes linear, branched, and cyclic thioalkoxy substituents, in which the O of, for example, the alkoxy groups is replaced by S.
As used above and herein, the terms “halogen” and “halo” may be understood in the broadest sense as being preferably fluorine, chlorine, bromine or iodine.
Whenever hydrogen (H) is mentioned herein, it could also be replaced by deuterium at each occurrence.
It is understood that when a molecular fragment is described as being a substituent or otherwise attached to another moiety, its name may be written as if it were a fragment (e.g. naphthyl, dibenzofuryl) or as if it were the whole molecule (e.g. naphthalene, dibenzofuran). As used herein, these different ways of designating a substituent or attached fragment are considered to be equivalent.
In one embodiment, the organic molecules according to the invention have an excited state lifetime of not more than 25 μs, of not more than 15 μs, in particular of not more than 10 μs, more preferably of not more than 8 μs or not more than 6 μs, and even more preferably of not more than 4 μs in a film of poly(methyl methacrylate) (PMMA) with 10% by weight of the organic molecule at room temperature.
In one embodiment of the invention, the organic molecules according to the invention represent thermally-activated delayed fluorescence (TADF) emitters, which exhibit a ΔEST value, which corresponds to the energy difference between the first excited singlet state (S1) and the first excited triplet state (T1), of less than 5000 cm−1, preferably less than 3000 cm−1, more preferably less than 1500 cm−1, even more preferably less than 1000 cm−1 or even less than 500 cm−1.
In a further embodiment of the invention, the organic molecules according to the invention have an emission peak in the visible or nearest ultraviolet range, i.e., in the range of a wavelength of from 380 to 800 nm, with a full width at half maximum of less than 0.50 eV, preferably less than 0.48 eV, more preferably less than 0.45 eV, even more preferably less than 0.43 eV or even less than 0.40 eV in a film of poly(methyl methacrylate) (PMMA) with 10% by weight of the organic molecule at room temperature.
Orbital and excited state energies can be determined either by means of experimental methods or by calculations employing quantum-chemical methods, in particular, density functional theory calculations. The energy of the highest occupied molecular orbital EHOMO is determined by methods known to the person skilled in the art from cyclic voltammetry measurements with an accuracy of 0.1 eV. The energy of the lowest unoccupied molecular orbital ELUMO is calculated as EHOMO+Egap, wherein Egap is determined as follows: For host compounds, the onset of the emission spectrum of a neat film of the host is used as Egap, unless stated otherwise. For emitter molecules, Egap is determined as the energy at which the excitation and emission spectra of a film with 10% by weight of emitter in PMMA cross.
The energy of the first excited triplet state T1 is determined from the onset of the emission spectrum at low temperature, typically at 77 K. For host compounds, where the first excited singlet state and the lowest triplet state are energetically separated by >0.4 eV, the phosphorescence is usually visible in a steady-state spectrum in 2-Me-THF. The triplet energy can thus be determined as the onset of the phosphorescence spectrum. For TADF emitter molecules, the energy of the first excited triplet state T1 is determined from the onset of the delayed emission spectrum at 77 K, if not otherwise stated measured in a film of PMMA with 10% by weight of emitter. For both host and emitter compounds, the energy of the first excited singlet state S1 is determined from the onset of the emission spectrum (measured as follows: TADF emitters: concentration of 10% by weight in a film of PMMA; hosts: neat film).
The onset of an emission spectrum is determined by computing the intersection of the tangent to the emission spectrum with the x-axis. The tangent to the emission spectrum is set at the high-energy side of the emission band and at the point at half maximum of the maximum intensity of the emission spectrum.
A further aspect of the invention relates to a method for preparing the organic molecules of the invention, wherein a substituted 2,4-dichloro-6-(chlorophenyl)triazine is used as a reactant:
According to the invention, a boronic ester can be used instead of a boronic acid.
For the reaction of a nitrogen heterocycle in a nucleophilic aromatic substitution with an aryl halide, preferably an aryl fluoride, typical conditions include the use of a base, such as tribasic potassium phosphate or sodium hydride, for example, in an aprotic polar solvent, such as dimethyl sulfoxide (DMSO) or N,N-dimethylformamide (DMF), for example.
An alternative synthesis route includes the introduction of a nitrogen heterocycle via copper- or palladium-catalyzed coupling to an aryl halide or aryl pseudohalide, preferably an aryl bromide, an aryl iodide, an aryl triflate or an aryl tosylate.
A further aspect of the invention relates to the use of an organic molecule according to the invention as a luminescent emitter or as an absorber, and/or as a host material and/or as an electron transport material, and/or as a hole injection material, and/or as a hole blocking material in an optoelectronic device.
The optoelectronic device may be understood in the broadest sense as any device based on organic materials that is suitable for emitting light in the visible or nearest ultraviolet (UV) range, i.e., in the range of a wavelength of from 380 to 800 nm. More preferably, the optoelectronic device may be able to emit light in the visible range, i.e., of from 400 nm to 800 nm.
In the context of such use, the optoelectronic device is more particularly selected from the group consisting of:
A light-emitting electrochemical cell consists of three layers, namely a cathode, an anode, and an active layer, which contains the organic molecule according to the invention.
In a preferred embodiment in the context of such use, the optoelectronic device is a device selected from the group consisting of an organic light emitting diode (OLED), a light emitting electrochemical cell (LEC), an organic laser, and a light-emitting transistor.
In one embodiment, the light-emitting layer of an organic light-emitting diode includes not only the organic molecules according to the invention but also a host material whose triplet (T1) and singlet (S1) energy levels are energetically higher than the triplet (T1) and singlet (S1) energy levels of the organic molecule.
A further aspect of the invention relates to a composition including or consisting of:
In a further embodiment of the invention, the composition has a photoluminescence quantum yield (PLQY) of more than 26%, preferably more than 40%, more preferably more than 60%, even more preferably more than 80% or even more than 90% at room temperature.
Compositions with at Least One Further Emitter
One embodiment of the invention relates to a composition including or consisting of:
The components or the compositions are chosen such that the sum of the weight of the components add up to 100%.
In a further embodiment of the invention, the composition has an emission peak in the visible or nearest ultraviolet range, i.e., in the range of a wavelength of from 380 to 800 nm.
In one embodiment of the invention, the at least one further emitter molecule F is a purely organic emitter.
In one embodiment of the invention, the at least one further emitter molecule F is a purely organic TADF emitter. Purely organic TADF emitters are known from the state of the art, e.g. Wong and Zysman-Colman (“Purely Organic Thermally Activated Delayed Fluorescence Materials for Organic Light-Emitting Diodes”, Adv. Mater. 2017 June; 29(22)).
In one embodiment of the invention, the at least one further emitter molecule F is a fluorescence emitter, in particular a blue, a green or a red fluorescence emitter.
In a further embodiment of the invention, the composition, containing the at least one further emitter molecule F shows an emission peak in the visible or nearest ultraviolet range, i.e., in the range of a wavelength of from 380 to 800 nm, with a full width at half maximum of less than 0.30 eV, in particular less than 0.25 eV, preferably less than 0.22 eV, more preferably less than 0.19 eV or even less than 0.17 eV at room temperature, with a lower limit of 0.05 eV.
In one embodiment, the light-emitting layer EML of an organic light-emitting diode of the invention includes (or essentially consists of) a composition including or consisting of:
Preferably, energy can be transferred from the host compound H to the one or more organic molecules of the invention, in particular transferred from the first excited triplet state T1 (H) of the host compound H to the first excited triplet state T1 (E) of the one or more organic molecules according to the invention and/or from the first excited singlet state S1(H) of the host compound H to the first excited singlet state S1(E) of the one or more organic molecules according to the invention.
In one embodiment, the host compound H has a highest occupied molecular orbital HOMO(H) having an energy EHOMO(H) in the range of from −5 eV to −6.5 eV and one organic molecule according to the invention E has a highest occupied molecular orbital HOMO(E) having an energy EHOMO(E), wherein EHOMO(H)>EHOMO(E).
In a further embodiment, the host compound H has a lowest unoccupied molecular orbital LUMO(H) having an energy ELUMO(H) and the one organic molecule according to the invention E has a lowest unoccupied molecular orbital LUMO(E) having an energy ELUMO(E), wherein ELUMO(H)>ELUMO(E).
In a further embodiment, the light-emitting layer EML of an organic light-emitting diode of the invention includes (or essentially consists of) a composition including or consisting of:
In one embodiment of the organic light-emitting diode of the invention, the host compound H has a highest occupied molecular orbital HOMO(H) having an energy EHOMO(H) in the range of from −5 eV to −6.5 eV and the at least one further host compound D has a highest occupied molecular orbital HOMO(D) having an energy EHOMO(D), wherein EHOMO(H)>EHOMO(D). The relation EHOMO(H)>EHOMO(D) favors an efficient hole transport.
In a further embodiment, the host compound H has a lowest unoccupied molecular orbital LUMO(H) having an energy ELUMO(H) and the at least one further host compound D has a lowest unoccupied molecular orbital LUMO(D) having an energy ELUMO(D), wherein ELUMO(H)>ELUMO(D). The relation ELUMO(H)>ELUMO(D) favors an efficient electron transport.
In one embodiment of the organic light-emitting diode of the invention, the host compound H has a highest occupied molecular orbital HOMO(H) having an energy EHOMO(H) and a lowest unoccupied molecular orbital LUMO(H) having an energy ELUMO(H), and
In a further embodiment, the light-emitting layer EML includes (or (essentially) consists of) a composition including or consisting of:
In a further embodiment, the light-emitting layer EML includes (or (essentially) consists of) a composition as described in Compositions with at least one further emitter, with the at least one further emitter molecule F as defined in Composition wherein the at least one further emitter molecule F is a blue fluorescence emitter.
In a further embodiment, the light-emitting layer EML includes (or (essentially) consists of) a composition as described in Compositions with at least one further emitter, with the at least one further emitter molecule F as defined in Composition wherein the at least one further emitter molecule F is a triplet-triplet annihilation (TTA) fluorescence emitter.
In a further embodiment, the light-emitting layer EML includes (or (essentially) consists of) a composition as described in Compositions with at least one further emitter, with the at least one further emitter molecule F as defined in Composition wherein the at least one further emitter molecule F is a green fluorescence emitter.
In a further embodiment, the light-emitting layer EML includes (or (essentially) consists of) a composition as described in Compositions with at least one further emitter, with the at least one further emitter molecule F as defined in Composition wherein the at least one further emitter molecule F is a red fluorescence emitter.
In one embodiment of the light-emitting layer EML including at least one further emitter molecule F, energy can be transferred from the one or more organic molecules of the invention E to the at least one further emitter molecule F, in particular transferred from the first excited singlet state S1(E) of one or more organic molecules of the invention E to the first excited singlet state S1(F) of the at least one further emitter molecule F.
In one embodiment, the first excited singlet state S1(H) of one host compound H of the light-emitting layer is higher in energy than the first excited singlet state S1(E) of the one or more organic molecules of the invention E: S1(H)>S1(E), and the first excited singlet state S1(H) of one host compound H is higher in energy than the first excited singlet state S1(F) of the at least one emitter molecule F: S1(H)>S1(F).
In one embodiment, the first excited triplet state T1 (H) of one host compound H is higher in energy than the first excited triplet state T1 (E) of the one or more organic molecules of the invention E: T1 (H)>T1 (E), and the first excited triplet state T1 (H) of one host compound H is higher in energy than the first excited triplet state T1(F) of the at least one emitter molecule F: T1(H)>T1(F).
In one embodiment, the first excited singlet state S1(E) of the one or more organic molecules of the invention E is higher in energy than the first excited singlet state S1(F) of the at least one emitter molecule F: S1(E)>S1(F).
In one embodiment, the first excited triplet state T1 (E) of the one or more organic molecules E of the invention is higher in energy than the first excited singlet state T1(F) of the at least one emitter molecule F: T1(E)>T1(F).
In one embodiment, the first excited triplet state T1 (E) of the one or more organic molecules E of the invention is higher in energy than the first excited singlet state T1(F) of the at least one emitter molecule F: T1(E)>T1(F), wherein the absolute value of the energy difference between T1(E) and T1(F) is larger than 0.3 eV, preferably larger than 0.4 eV, or even larger than 0.5 eV.
In one embodiment, the host compound H has a highest occupied molecular orbital HOMO(H) having an energy EHOMO(H) and a lowest unoccupied molecular orbital LUMO(H) having an energy ELUMO(H), and
the one organic molecule according to the invention E has a highest occupied molecular orbital HOMO(E) having an energy EHOMO(E) and a lowest unoccupied molecular orbital LUMO(E) having an energy ELUMO(E),
the at least one further emitter molecule F has a highest occupied molecular orbital HOMO(F) having an energy EHOMO(F) and a lowest unoccupied molecular orbital LUMO(E) having an energy ELUMO(F),
In a further aspect, the invention relates to an optoelectronic device including an organic molecule or a composition as described herein, more particularly in the form of a device selected from the group consisting of organic light-emitting diode (OLED), light-emitting electrochemical cell, OLED sensor (more particularly gas and vapour sensors not hermetically externally shielded), organic diode, organic solar cell, organic transistor, organic field-effect transistor, organic laser and down-conversion element.
In a preferred embodiment, the optoelectronic device is a device selected from the group consisting of an organic light emitting diode (OLED), a light emitting electrochemical cell (LEC), and a light-emitting transistor.
In one embodiment of the optoelectronic device of the invention, the organic molecule according to the invention is used as emission material in a light-emitting layer EML.
In one embodiment of the optoelectronic device of the invention, the light-emitting layer EML consists of the composition according to the invention described herein.
When the optoelectronic device is an OLED, it may, for example, exhibit the following layer structure:
Furthermore, the optoelectronic device may optionally include one or more protective layers protecting the device from damaging exposure to harmful species in the environment including, exemplarily moisture, vapor and/or gases.
In one embodiment of the invention, the optoelectronic device is an OLED, which exhibits the following inverted layer structure:
In one embodiment of the invention, the optoelectronic device is an OLED, which may exhibit stacked architecture. In this architecture, contrary to the typical arrangement, where the OLEDs are placed side by side, the individual units are stacked on top of each other. Blended light may be generated with OLEDs exhibiting a stacked architecture, in particular white light may be generated by stacking blue, green and red OLEDs. Furthermore, the OLED exhibiting a stacked architecture may optionally include a charge generation layer (CGL), which is typically located between two OLED subunits and typically consists of an n-doped layer and a p-doped layer with the n-doped layer of one CGL being typically located closer to the anode layer.
In one embodiment of the invention, the optoelectronic device is an OLED, which includes two or more emission layers between anode and cathode. In particular, this so-called tandem OLED includes three emission layers, wherein one emission layer emits red light, one emission layer emits green light and one emission layer emits blue light, and optionally may include further layers such as charge generation layers, blocking or transporting layers between the individual emission layers. In a further embodiment, the emission layers are adjacently stacked. In a further embodiment, the tandem OLED includes a charge generation layer between each two emission layers. In addition, adjacent emission layers or emission layers separated by a charge generation layer may be merged.
The substrate may be formed by any material or composition of materials. Most frequently, glass slides are used as substrates. Alternatively, thin metal layers (e.g., copper, gold, silver or aluminum films) or plastic films or slides may be used. This may allow a higher degree of flexibility. The anode layer A is mostly composed of materials allowing to obtain an (essentially) transparent film. As at least one of the two electrodes should be (essentially) transparent in order to allow light emission from the OLED, either the anode layer A or the cathode layer C is transparent. Preferably, the anode layer A includes a large content or even consists of transparent conductive oxides (TCOs). Such anode layer A may, for example, include indium tin oxide, aluminum zinc oxide, fluorine doped tin oxide, indium zinc oxide, PbO, SnO, zirconium oxide, molybdenum oxide, vanadium oxide, wolfram oxide, graphite, doped Si, doped Ge, doped GaAs, doped polyaniline, doped polypyrrol and/or doped polythiophene.
Preferably, the anode layer A (essentially) consists of indium tin oxide (ITO) (e.g., (InO3)0.9(SnO2)0.1). The roughness of the anode layer A caused by the transparent conductive oxides (TCOs) may be compensated by using a hole injection layer (HIL). Further, the HIL may facilitate the injection of quasi charge carriers (i.e., holes) in that the transport of the quasi charge carriers from the TCO to the hole transport layer (HTL) is facilitated. The hole injection layer (HIL) may include poly-3,4-ethylenedioxy thiophene (PEDOT), polystyrene sulfonate (PSS), MoO2, V2O5, CuPC or CuI, in particular a mixture of PEDOT and PSS. The hole injection layer (HIL) may also prevent the diffusion of metals from the anode layer A into the hole transport layer (HTL). The HIL may include PEDOT:PSS (poly-3,4-ethylenedioxy thiophene: polystyrene sulfonate), PEDOT (poly-3,4-ethylenedioxy thiophene), mMTDATA (4,4′,4″-tris[phenyl(m-tolyl)amino]triphenylamine), Spiro-TAD (2,2′,7,7′-tetrakis(n,n-diphenylamino)-9,9′-spirobifluorene), DNTPD (N1,N1′-(biphenyl-4,4′-diyl)bis(N1-phenyl-N4,N4-di-m-tolylbenzene-1,4-diamine), NPB (N,N′-nis-(1-naphthalenyl)-N,N′-bis-phenyl-(1,1′-biphenyl)-4,4′-diamine), NPNPB (N,N′-diphenyl-N,N′-di-[4-(N,N-diphenyl-amino)phenyl]benzidine), MeO-TPD (N,N,N′,N′-tetrakis(4-methoxyphenyl)benzidine), HAT-CN (1,4,5,8,9,11-hexaazatriphenylen-hexacarbonitrile) and/or Spiro-NPD (N,N′-diphenyl-N,N′-bis-(1-naphthyl)-9,9′-spirobifluorene-2,7-diamine).
Adjacent to the anode layer A or hole injection layer (HIL) typically a hole transport layer (HTL) is located. Herein, any hole transport compound may be used. Exemplarily, electron-rich heteroaromatic compounds such as triarylamines and/or carbazoles may be used as hole transport compound. The HTL may decrease the energy barrier between the anode layer A and the light-emitting layer EML. The hole transport layer (HTL) may also be an electron blocking layer (EBL). Preferably, hole transport compounds bear comparably high energy levels of their triplet states T1. Exemplarily the hole transport layer (HTL) may include a star-shaped heterocycle such as tris(4-carbazoyl-9-ylphenyl)amine (TCTA), poly-TPD (poly(4-butylphenyl-diphenyl-amine)), [alpha]-NPD (poly(4-butylphenyl-diphenyl-amine)), TAPC (4,4′-cyclohexyliden-bis[N,N-bis(4-methylphenyl)benzenamine]), 2-TNATA (4,4′,4″-tris[2-naphthyl(phenyl)amino]triphenylamine), Spiro-TAD, DNTPD, NPB, NPNPB, MeO-TPD, HAT-CN and/or TrisPcz (9,9′-diphenyl-6-(9-phenyl-9H-carbazol-3-yl)-9H,9′H-3,3′-bicarbazole). In addition, the HTL may include a p-doped layer, which may be composed of an inorganic or organic dopant in an organic hole-transporting matrix. Transition metal oxides such as vanadium oxide, molybdenum oxide or tungsten oxide may be used as the inorganic dopant. Tetrafluorotetracyanoquinodimethane (F4-TCNQ), copper-pentafluorobenzoate (Cu(I)pFBz) or transition metal complexes may be used as the organic dopant.
The EBL may include mCP (1,3-bis(carbazol-9-yl)benzene), TCTA, 2-TNATA, mCBP (3,3-di(9H-carbazol-9-yl)biphenyl), tris-Pcz, CzSi (9-(4-tert-Butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole), and/or DCB (N,N′-dicarbazolyl-1,4-dimethylbenzene).
Adjacent to the hole transport layer (HTL), typically, the light-emitting layer EML is located. The light-emitting layer EML includes at least one light emitting molecule. Particularly, the EML includes at least one light emitting molecule according to the invention. Typically, the EML additionally includes one or more host material. Exemplarily, the host material is selected from CBP (4,4′-Bis-(N-carbazolyl)-biphenyl), mCP, mCBP Sif87 (dibenzo[b,d]thiophen-2-yltriphenylsilane), CzSi, Sif88 (dibenzo[b,d]thiophen-2-yl)diphenylsilane), DPEPO (bis[2-(diphenylphosphino)phenyl]ether oxide), 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzothiophen-2-yl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzofuranyl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzothiophenyl)phenyl]-9H-carbazole, T2T (2,4,6-tris(biphenyl-3-yl)-1,3,5-triazine), T3T (2,4,6-tris(triphenyl-3-yl)-1,3,5-triazine) and/or TST (2,4,6-tris(9,9′-spirobifluorene-2-yl)-1,3,5-triazine). The host material typically should be selected to exhibit first triplet (T1) and first singlet (S1) energy levels, which are energetically higher than the first triplet (T1) and first singlet (S1) energy levels of the organic molecule.
In one embodiment of the invention, the EML includes a so-called mixed-host system with at least one hole-dominant host and one electron-dominant host. In a particular embodiment, the EML includes exactly one light emitting molecule species according to the invention and a mixed-host system including T2T as the electron-dominant host and a host selected from CBP, mCP, mCBP, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzothiophen-2-yl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzofuranyl)phenyl]-9H-carbazole and 9-[3,5-bis(2-dibenzothiophenyl)phenyl]-9H-carbazole as the hole-dominant host. In a further embodiment the EML includes 50-80% by weight, preferably 60-75% by weight of a host selected from CBP, mCP, mCBP, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzothiophen-2-yl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzofuranyl)phenyl]-9H-carbazole and 9-[3,5-bis(2-dibenzothiophenyl)phenyl]-9H-carbazole; 10-45% by weight, preferably 15-30% by weight of T2T and 5-40% by weight, preferably 10-30% by weight of light emitting molecule according to the invention.
Adjacent to the light-emitting layer EML an electron transport layer (ETL) may be located. Herein, any electron transporter may be used. Exemplarily, electron-poor compounds such as, e.g., benzimidazoles, pyridines, triazoles, oxadiazoles (e.g., 1,3,4-oxadiazole), phosphinoxides and sulfone, may be used. An electron transporter may also be a star-shaped heterocycle such as 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (TPBi). The ETL may include NBphen (2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline), Alq3 (Aluminum-tris(8-hydroxyquinoline)), TSPO1 (diphenyl-4-triphenylsilylphenyl-phosphinoxide), BPyTP2 (2,7-di(2,2′-bipyridin-5-yl)triphenyle), Sif87 (dibenzo[b,d]thiophen-2-yltriphenylsilane), Sif88 (dibenzo[b,d]thiophen-2-yl)diphenylsilane), BmPyPhB (1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene) and/or BTB (4,4′-bis-[2-(4,6-diphenyl-1,3,5-triazinyl)]-1,1′-biphenyl). Optionally, the ETL may be doped with materials such as Liq. The electron transport layer (ETL) may also block holes or a hole blocking layer (HBL) is introduced.
The HBL may, for example, include BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline=Bathocuproine), BAlq (bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum), NBphen (2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline), Alq3 (Aluminum-tris(8-hydroxyquinoline)), TSPO1 (diphenyl-4-triphenylsilylphenyl-phosphinoxide), T2T (2,4,6-tris(biphenyl-3-yl)-1,3,5-triazine), T3T (2,4,6-tris(triphenyl-3-yl)-1,3,5-triazine), TST (2,4,6-tris(9,9′-spirobifluorene-2-yl)-1,3,5-triazine), and/or TCB/TCP (1,3,5-tris(N-carbazolyl)benzol/1,3,5-tris(carbazol)-9-yl) benzene).
A cathode layer C may be located adjacent to the electron transport layer (ETL). For example, the cathode layer C may include or may consist of a metal (e.g., Al, Au, Ag, Pt, Cu, Zn, Ni, Fe, Pb, LiF, Ca, Ba, Mg, In, W, or Pd) or a metal alloy. For practical reasons, the cathode layer may also consist of (essentially) non-transparent metals such as Mg, Ca or Al. Alternatively or additionally, the cathode layer C may also include graphite and/or carbon nanotubes (CNTs). Alternatively, the cathode layer C may also consist of nanoscalic silver wires.
An OLED may further, optionally, include a protection layer between the electron transport layer (ETL) and the cathode layer C (which may be designated as electron injection layer (EIL)). This layer may include lithium fluoride, cesium fluoride, silver, Liq (8-hydroxyquinolinolatolithium), Li2O, BaF2, MgO and/or NaF.
Optionally, also the electron transport layer (ETL) and/or a hole blocking layer (HBL) may include one or more host compounds.
In order to modify the emission spectrum and/or the absorption spectrum of the light-emitting layer EML further, the light-emitting layer EML may further include one or more additional emitter molecule F. Such an emitter molecule F may be any emitter molecule known in the art. Preferably such an emitter molecule F is a molecule with a structure differing from the structure of the molecules according to the invention. The emitter molecule F may optionally be a TADF emitter. Alternatively, the emitter molecule F may optionally be a fluorescent and/or phosphorescent emitter molecule which is able to shift the emission spectrum and/or the absorption spectrum of the light-emitting layer EML. For example, the triplet and/or singlet excitons may be transferred from the emitter molecule according to the invention to the emitter molecule F before relaxing to the ground state S0 by emitting light typically red-shifted in comparison to the light emitted by emitter molecule E. Optionally, the emitter molecule F may also provoke two-photon effects (i.e., the absorption of two photons of half the energy of the absorption maximum).
Optionally, an optoelectronic device (e.g., an OLED) may, for example, be an essentially white optoelectronic device. Exemplarily such white optoelectronic device may include at least one (deep) blue emitter molecule and one or more emitter molecules emitting green and/or red light. Then, there may also optionally be energy transmittance between two or more molecules as described above.
As used herein, if not defined more specifically in the particular context, the designation of the colors of emitted and/or absorbed light is as follows:
With respect to emitter molecules, such colors refer to the emission maximum. Therefore, exemplarily, a deep blue emitter has an emission maximum in the range of from >420 to 480 nm, a sky-blue emitter has an emission maximum in the range of from >480 to 500 nm, a green emitter has an emission maximum in a range of from >500 to 560 nm, and a red emitter has an emission maximum in a range of from >620 to 800 nm.
A green emitter may preferably have an emission maximum between 500 and 560 nm, more preferably between 510 and 550 nm, and even more preferably between 520 and 540 nm.
A further embodiment of the present invention relates to an OLED, which emits light with CIEx and CIEy color coordinates close to the CIEx (=0.170) and CIEy (=0.797) color coordinates of the primary color green (CIEx=0.170 and CIEy=0.797) as defined by ITU-R Recommendation BT.2020 (Rec. 2020) and thus is suited for the use in Ultra High Definition (UHD) displays, e.g. UHD-TVs. In this context, the term “close to” refers to the ranges of CIEx and CIEy coordinates provided at the end of this paragraph. In commercial applications, typically top-emitting (top-electrode is transparent) devices are used, whereas test devices as used throughout the present application represent bottom-emitting devices (bottom-electrode and substrate are transparent). Accordingly, a further aspect of the present invention relates to an OLED, whose emission exhibits a CIEx color coordinate of between 0.06 and 0.34, preferably between 0.07 and 0.29, more preferably between 0.09 and 0.24 or even more preferably between 0.12 and 0.22 or even between 0.14 and 0.19 and/or a CIEy color coordinate of between 0.44 and 0.84, preferably between 0.55 and 0.83, more preferably between 0.65 and 0.82 or even more preferably between 0.70 and 0.81 or even between 0.75 and 0.8.
Accordingly, a further aspect of the present invention relates to an OLED, which exhibits an external quantum efficiency at 14500 cd/m2 of more than 10%, more preferably of more than 13%, more preferably of more than 15%, even more preferably of more than 17% or even more than 20% and/or exhibits an emission maximum between 495 nm and 580 nm, preferably between 500 nm and 560 nm, more preferably between 510 nm and 550 nm, even more preferably between 515 nm and 540 nm and/or exhibits a LT97 value at 14500 cd/m2 of more than 100 h, preferably more than 250 h, more preferably more than 500 h, even more preferably more than 750 h or even more than 1000 h.
A further aspect of the present invention relates to an OLED, which emits light at a distinct color point. According to the present invention, the OLED emits light with a narrow emission band (small full width at half maximum (FWHM)). In one aspect, the OLED according to the invention emits light with a FWHM of the main emission peak of less than 0.50 eV, preferably less than 0.48 eV, more preferably less than 0.45 eV, even more preferably less than 0.43 eV or even less than 0.40 eV.
In a further aspect, the invention relates to a method for producing an optoelectronic component. In this case an organic molecule of the invention is used.
The organic electroluminescent device, in particular the OLED according to the present invention can be fabricated by any means of vapor deposition and/or liquid processing. Accordingly, at least one layer is
The methods used to fabricate the organic electroluminescent device, in particular the OLED according to the present invention are known in the art. The different layers are individually and successively deposited on a suitable substrate by means of subsequent deposition processes. The individual layers may be deposited using the same or differing deposition methods.
Vapor deposition processes may include thermal (co)evaporation, chemical vapor deposition and physical vapor deposition. For active matrix OLED display, an AMOLED backplane is used as substrate. The individual layer may be processed from solutions or dispersions employing adequate solvents. Solution deposition processes exemplarily include spin coating, dip coating and jet printing. Liquid processing may optionally be carried out in an inert atmosphere (e.g., in a nitrogen atmosphere) and the solvent may optionally be completely or partially removed by means known in the state of the art.
The general synthesis scheme provides a synthesis scheme for organic molecules according to the invention.
Under nitrogen atmosphere, dry THF was added to (3-chloro-iodobenzene (1.00 equivalents, CAS 625-99-0), cooled down to −20° C. followed by nitrogen-sparging for 10 min. Isopropylmagnesium chloride-lithium chloride complex solution in THF (1.3 M, 1.10 equivalents, CAS 745038-86-2) was added dropwise to the solution and the mixture was stirred at −20° C. for 1 h (solution A). In a separate flask under nitrogen atmosphere, dry THF was added to cyanuric chloride (1.50 equivalents, CAS 108-77-0), cooled down to −20° C. followed by nitrogen-sparging for 10 min (Solution B). Solution A was then transferred via cannula into solution B and the mixture was heated to 60° C. for 2 h. Subsequently, the reaction mixture was poured into ice water and extracted with ethyl acetate. The combined organic phases were dried by magnesium sulfate and the solvent was removed under reduced pressure. The crude product was purified by recrystallization. The product was obtained as a solid.
Under nitrogen atmosphere, dry THF was added to (4-chloro-iodobenzene (1.00 equivalents, CAS 625-99-0), cooled down to −20° C. followed by nitrogen-sparging for 10 min. Isopropylmagnesium chloride-lithium chloride complex solution in THF (1.3 M, 1.10 equivalents, CAS 745038-86-2) was added dropwise to the solution and the mixture was stirred at −20° C. for 1 h (solution A). In a separate flask under nitrogen atmosphere, dry THF was added to cyanuric chloride (1.50 equivalents, CAS 108-77-0), cooled down to −20° C. followed by nitrogen-sparging for 10 min (Solution B). Solution A was then transferred via cannula into solution B and the mixture was heated to 60° C. for 2 h. Subsequently, the reaction mixture was poured into ice water and extracted with ethyl acetate. The combined organic phases were dried by magnesium sulfate and the solvent was removed under reduced pressure. The crude product was purified by recrystallization. The product was obtained as a solid.
Under nitrogen atmosphere, a mixture of dioxane and water (ratio of 9:1) was added to (4-chloro-2-fluorophenyl)boronic acid (2.20 equivalents, CAS 160591-91-3), 2,4-dichloro-6-(3-chlorophenyl)-1,3,5-triazine (1.00 equivalents, product of AAV0-1), potassium carbonate (3.40 equivalents), and [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (0.04 equivalents, CAS 72287-26-4), followed by nitrogen-sparging for 10 min. The reaction mixture was stirred under reflux (heating plate set to 110° C.) for 1 h. Subsequently, the reaction mixture was poured into ice water, the precipitate was filtered and washed with water as well as ethanol. The crude product was purified by recrystallization. The product was obtained as a solid.
Under nitrogen atmosphere, a mixture of THF and water (ratio of 10:1) was added to (4-chloro-2-fluorophenyl)boronic acid (2.10 equivalents, CAS 160591-91-3), 2,4-dichloro-6-(4-chlorophenyl)-1,3,5-triazine (1.00 equivalents, product of AAV0-2), potassium carbonate (3.40 equivalents), and tetrakis(triphenylphosphine)palladium(0) (0.04 equivalents, CAS 14221-01-3), followed by nitrogen-sparging for 10 min. The reaction mixture was stirred at 60° C. for 3 h. Subsequently, the reaction mixture was poured into ice-cold water, the precipitate was filtered and washed with water as well as ethanol. The crude product was heated in ethanol under reflux for 1 h, hot-filtered and washed with ethanol. The product was obtained as a solid.
Under nitrogen atmosphere, 2,4-bis(4-chloro-2-fluorophenyl)-6-(3-chlorophenyl)-1,3,5-triazine (1.00 equivalents, product of AAV1-1), the corresponding donor molecule D-H (2.20 equivalents), and tribasic potassium phosphate (3.00 equivalents) were suspended in dry DMSO and stirred at 80° C. for 20 h. Subsequently, the reaction mixture was poured into a stirred mixture of water and ice, followed by the addition of ethyl acetate. The precipitate was filtered off and washed with water and ethyl acetate. The product was obtained as a solid.
The reaction conditions were analogous to AAV2-1, but 2,4-bis(4-chloro-2-fluorophenyl)-6-(4-chlorophenyl)-1,3,5-triazine (product of AAV1-2) was used as the reactant.
Under nitrogen atmosphere, a mixture of dioxane and water (ratio of 9:1 was added to the product of AAV2-1 (1.00 equivalents), (3-cyanophenyl)boronic acid (4.5 equivalents, CAS 150255-96-2), tris(dibenzylideneacetone)dipalladium(0) (0.04 equivalents, CAS 51364-51-3), 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (X-Phos, 0.16 equivalents, CAS 564483-18-7), and tribasic potassium phosphate (4.00 equivalents), followed by nitrogen-sparging for 5 min. The reaction mixture was stirred under reflux for 2 days, then cooled to room temperature, and poured into ice-cold water. The precipitate was filtered off and washed with water as well as isopropyl alcohol. The crude product was heated under reflux in acetonitrile for 2 h, hot-filtered, and washed with acetonitrile. Filtration through a short pad of silica using dichloromethane as solvent yields the product as a solid.
The reaction conditions were analogous to AAV3-1, but the product of AAV2-2 was used as the reactant.
In particular, the donor molecule D-H was a 3,6-substituted carbazole (e.g., 3,6-dimethylcarbazole, 3,6-diphenylcarbazole, 3,6-di-tert-butylcarbazole), a 2,7-substituted carbazole (e.g., 2,7-dimethylcarbazole, 2,7-diphenylcarbazole, 2,7-di-tert-butylcarbazole), a 1,8-substituted carbazole (e.g., 1,8-dimethylcarbazole, 1,8-diphenylcarbazole, 1,8-di-tert-butylcarbazole), a 1-substituted carbazole (e.g., 1-methylcarbazole, 1-phenylcarbazole, 1-tert-butylcarbazole), a 2-substituted carbazole (e.g., 2-methylcarbazole, 2-phenylcarbazole, 2-tert-butylcarbazole), or a 3-substituted carbazole (e.g., 3-methylcarbazole, 3-phenylcarbazole, 3-tert-butylcarbazole).
Exemplarily a halogen-substituted carbazole, particularly 3-bromocarbazole, can be used as D-H.
In a subsequent reaction a boronic acid ester functional group or boronic acid functional group may be exemplarily introduced at the position of the one or more halogen substituents, which was introduced via D-H, to yield the corresponding carbazol-3-ylboronic acid ester or carbazol-3-ylboronic acid, e.g., via the reaction with bis(pinacolato)diboron (CAS No. 73183-34-3). Subsequently, one or more substituents Ra may be introduced in place of the boronic acid ester group or the boronic acid group via a coupling reaction with the corresponding halogenated reactant Ra-Hal, preferably Ra—Cl and Ra—Br.
Alternatively, one or more substituents Ra may be introduced at the position of the one or more halogen substituents, which was introduced via D-H, via the reaction with a boronic acid of the substituent Ra [Ra—B(OH)2] or a corresponding boronic acid ester.
HPLC-MS:
HPLC-MS analysis was performed on an HPLC by Agilent (1100 series) with MS-detector (Thermo LTQ XL).
Exemplary a typical HPLC method was as follows: a reverse phase column 4.6 mm×150 mm, particle size 3.5 μm from Agilent (ZORBAX Eclipse Plus 95 Å C18, 4.6×150 mm, 3.5 μm HPLC column) was used in the HPLC. The HPLC-MS measurements were performed at room temperature (rt) with the following gradients
using the following solvent mixtures:
An injection volume of 5 μL from a solution with a concentration of 0.5 mg/mL of the analyte was taken for the measurements.
Ionization of the probe was performed using an APCI (atmospheric pressure chemical ionization) source either in positive (APCI+) or negative (APCI−) ionization mode.
Cyclic voltammograms were measured from solutions having concentration of 10−3 mol/L of the organic molecules in dichloromethane or a suitable solvent and a suitable supporting electrolyte (e.g. 0.1 mol/L of tetrabutylammonium hexafluorophosphate). The measurements were conducted at room temperature under nitrogen atmosphere with a three-electrode assembly (Working and counter electrodes: Pt wire, reference electrode: Pt wire) and calibrated using FeCp2/FeCp2+ as internal standard. The HOMO data was corrected using ferrocene as internal standard against a saturated calomel electrode (SCE).
Molecular structures were optimized employing the BP86 functional and the resolution of identity approach (RI). Excitation energies were calculated using the (BP86) optimized structures employing Time-Dependent DFT (TD-DFT) methods. Orbital and excited state energies were calculated with the B3LYP functional. Def2-SVP basis sets (and an m4-grid for numerical integration were used. The Turbomole program package was used for all calculations.
Sample pretreatment: Spin-coating
Apparatus: Spin150, SPS euro.
The sample concentration was 10 mg/ml, dissolved in a suitable solvent.
Program: 1) 3 s at 400 U/min; 2) 20 s at 1000 U/min at 1000 Upm/s. 3) 10 s at 4000 U/min at 1000 Upm/s. After coating, the films were tried at 70° C. for 1 min.
Steady-state emission spectroscopy was measured by a Horiba Scientific, Modell FluoroMax-4 equipped with a 150 W Xenon-Arc lamp, excitation- and emissions monochromators and a Hamamatsu R928 photomultiplier and a time-correlated single-photon counting option. Emissions and excitation spectra were corrected using standard correction fits.
Excited state lifetimes were determined employing the same system using the TCSPC method with FM-2013 equipment and a Horiba Yvon TCSPC hub.
Excitation Sources:
Data analysis (exponential fit) was done using the software suite DataStation and DAS6 analysis software. The fit was specified using the chi-squared-test.
For photoluminescence quantum yield (PLQY) measurements an Absolute PL Quantum Yield Measurement C9920-03G system (Hamamatsu Photonics) was used. Quantum yields and CIE coordinates were determined using the software U6039-05 version 3.6.0.
Emission maxima were given in nm, quantum yields CD in % and CIE coordinates as x,y values.
PLQY was determined using the following protocol:
Quality assurance: Anthracene in ethanol (known concentration) was used as reference
Excitation wavelength: the absorption maximum of the organic molecule was determined and the molecule was excited using this wavelength
Measurement
Quantum yields were measured for sample of solutions or films under nitrogen atmosphere. The yield was calculated using the equation:
Optoelectronic devices, such as OLED devices, including an organic molecule according to the invention can be produced via vacuum-deposition methods. If a layer contains more than one compound, the weight-percentage of one or more compounds was given in %. The total weight-percentage values amount to 100%, thus if a value was not given, the fraction of this compound equals to the difference between the given values and 100%.
The not fully optimized OLEDs were characterized using standard methods and measuring electroluminescence spectra, the external quantum efficiency (in %) in dependency on the intensity, calculated using the light detected by the photodiode, and the current. The OLED device lifetime was extracted from the change of the luminance during operation at constant current density. The LT50 value corresponds to the time, where the measured luminance decreased to 50% of the initial luminance, analogously LT80 corresponds to the time point, at which the measured luminance decreased to 80% of the initial luminance, and LT 95 corresponds to the time point, at which the measured luminance decreased to 95% of the initial luminance etc.
Accelerated lifetime measurements were performed (e.g. applying increased current densities). For example, LT80 values at 500 cd/m2 were determined using the following equation:
The values correspond to the average of several pixels (typically two to eight), the standard deviation between these pixels was given. The figures show the data series for one OLED pixel.
Example 1 was synthesized according to AAV0-1 (yield 58%), AAV1-1 (yield 55%), AAV2-1 (yield 53%), and AA V3-1 (yield 75%).
MS (HPLC-MS), m/z (retention time): 1247.90 6.13 min).
Example 2 was synthesized according to AAV0-2 (yield 67%), AAV1-2 (yield 47%), AAV2-2 (yield 25%), and AA V3-2 (yield 74%).
MS (HPLC-MS), m/z (retention time): 1248.1 (6.23 min).
Example 1 was tested in an optoelectronic device in the form of OLED D1, which was fabricated with the following layer structure:
OLED D1 yielded an external quantum efficiency (EQE) at 1000 cd/m2 of 18.4%. The emission maximum was at 514 nm with a FWHM of 76 nm at 6.4 V. The corresponding CIEx value was 0.27 and the CIEy value was 0.59. A LT95-value at 1200 cd/m2 of 142 h was determined.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20187628.1 | Jul 2020 | EP | regional |
This application is a U.S. National Phase Patent Application of International Patent Application Number PCT/EP2021/070475, filed on Jul. 22, 2021, which claims priority to European Patent Application Number 20187628.1, filed on Jul. 24, 2020, the entire content of all of which is incorporated herein by reference. The invention relates to light-emitting organic molecules and their use in organic light-emitting diodes (OLEDs) and in other optoelectronic devices.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/070475 | 7/22/2021 | WO |
