Patent Application
20100066241
The present invention relates to novel organic electroluminescent compounds, and organic electroluminescent devices employing the same in an electroluminescent layer. More specifically, the invention relates to novel organic electroluminescent compounds to be employed as blue electroluminescent material, and organic electroluminescent devices employing the same as dopant.
Among display devices, electroluminescence devices (EL devices) are self-luminescent display devices showing the advantage of wide angle of view, excellent contrast and rapid response rate. Eastman Kodak developed an organic EL device which employs a low molecular weight aromatic diamine and an aluminum complex as material for forming an EL layer, in 1987 for the first time [Appl. Phys. Lett. 51, 913, 1987].
The most important factor to determine the performances such as luminous efficiency, lifetime or the like in an organic EL device is electroluminescent material. Several properties required for such electroluminescent materials include that the material should have high fluorescent quantum yield in solid state and high mobility of electrons and holes, is not easily decomposed during vapor-deposition in vacuo, and forms uniform and stable thin film.
Organic electroluminescent materials can be generally classified into high-molecular materials and low-molecular materials. The low-molecular materials include metal complexes and thoroughly organic electroluminescent materials which do not contain metal, from the aspect of molecular structure. Such electroluminescent materials include chelate complexes such as tris(8-quinolinolato)aluminum complexes, coumarin derivatives, tetraphenylbutadiene derivatives, bis(styrylarylene) derivatives, and oxadiazole derivatives. From those materials, it is reported that light emission of visible region from blue to red can be obtained; and realization of full-colored display devices is expected thereby.
In the meanwhile, for conventional blue materials, a number of materials have been developed and commercialized since the development of diphenylvinyl-biphenyl (DPVBi) (Compound a) by Idemitsu-Kosan. In addition to the blue material system from Idemitsu-Kosan, dinaphthylanthracene (DNA) (Compound b) of Kodac, tetra(t-butyl)perylene (Compound c) system or the like have been known. However, extensive research and development should be performed with respect to these materials. The distryl compound system of Idemitsu-Kosan, which is known to have highest efficiency up to now, has 6 lm/W power efficiency and beneficial device lifetime of more than 30,000 hr. However, when it is applied to a full-colored display, the lifetime is merely several thousand hours, owing to decrease of color purity over operation time. In case of blue electroluminescence, it becomes advantageous from the aspect of the luminous efficiency, if the electroluminescent wavelength is shifted a little toward longer wavelength. However, it is not easy to apply the material to a display of high quality because of unsatisfactory color purity in blue. Furthermore, the research and development of such materials are urgent because of the problems in color purity, efficiency and thermal stability.
With intensive efforts to overcome the problems of conventional techniques as described above, the present inventors have invented novel electroluminescent compounds to realize an organic electroluminescent device having excellent luminous efficiency and noticeably improved lifetime.
The object of the present invention is to provide organic electroluminescent compounds having the backbone to give more excellent electroluminescent properties, longer device life and appropriate color coordinate, as compared to those of conventional dopant materials, with overcoming disadvantages of them.
Another object of the invention is to provide organic electroluminescent devices of high efficiency and long life, which employ said organic electroluminescent compounds as electroluminescent material.
The present invention relates to organic electroluminescent compounds represented by Chemical Formula (1), and organic electroluminescent devices comprising the same. Since the organic electroluminescent compounds according to the invention show good luminous efficiency and excellent color purity and life property of material, OLED's having very good operation life can be manufactured therefrom.
In Chemical Formula (1), L1 is a substituent selected from the following structures;
A and B independently represent a chemical bond, or a substituent selected from the following structures;
Ar1 and Ar2 independently represent a chemical bond, or (C6-C60)arylene, (C3-C60)heteroarylene, 5- or 6-membered heterocycloalkylene containing one or more heteroatom(s) selected from N, O and S, (C3-C60)cycloalkylene, (C2-C60)alkenylene, (C2-C60)alkynylene, (Cl-C60)alkylenoxy, (C6-C60)arylenoxy or (C6-C60)arylenethio; the arylene, heteroarylene, heterocycloalkylene, cycloalkylene, alkenylene, alkynylene, alkylenoxy, arylenoxy or arylenethio of Ar1 and Ar2 may be further substituted by one or more substituent(s) selected from a group consisting of halogen, (C1-C60)alkyl, halo(C1-C60)alkyl, (C6-C60)aryl, (C3-C60)heteroaryl, 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O, S and Si, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C1-C60)alkoxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro and hydroxyl;
R1 through R20 independently represent hydrogen, halogen, (C1-C60)alkyl, (C6-C60)aryl, (C3-C60)heteroaryl, 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C1-C60)alkoxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro or hydroxyl, or each of R1 through R20 may be linked to an adjacent substituent via (C3-C60)alkylene or (C3-C60)alkenylene with or without a fused ring to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring;
R21 through R26 independently represent hydrogen, halogen, (C1-C60)alkyl, (C6-C60)aryl, (C3-C60)heteroaryl, 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C1-C60)alkoxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro or hydroxyl;
X1, X2, Y1 and Y2 independently represent a chemical bond, or —C(R31)(R32)—, —N(R33)—, —S—, —O—, —Si(R34)(R35)—, —P(R36)—, —C(═O)—, —B(R37)—, —In(R38)—, —Se—, —Ge(R39)(R40)—, —Sn(R41)(R42)—, —Ga(R43)— or —(R44)C═C(R45)—;
R31 through R45 independently represent hydrogen, halogen, (C1-C60)alkyl, (C6-C60)aryl, (C3-C60)heteroaryl, 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O, S and Si, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C1-C60)alkoxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro or hydroxyl, or R31 and R32, R34 and R35, R39 and R40, R41 and R42, or R44 and R45 may be linked via (C3-C60)alkylene or (C3-C60)alkenylene with or without a fused ring to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring;
the alkyl, aryl, heteroaryl, heterocycloalkyl, cycloalkyl, trialkylsilyl, dialkylarylsilyl, triarylsilyl, adamantyl, bicycloalkyl, alkenyl, alkynyl, alkylamino or arylamino of R1 through R26 and R31 through R45 may be further substituted by one or more substituent(s) selected from halogen, (C1-C60)alkyl with or without halogen substituent(s), (C6-C60)aryl, (C3-C60)heteroaryl with or without (C6-C60)aryl substituent(s), 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C1-C60)alkoxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro and hydroxyl; and
m and n independently represent an integer from 0 to 4;
provided that, if
represents
both X1 and X2 represent NR33, and both Y1 and Y2 represent a chemical bond, then R33 does not represent hydrogen or (C1-C5)alkyl.
Referring now to the Drawings,
The terms “alkyl”, “alkoxy” and other substituents containing “alkyl” moiety described herein include both linear and branched species.
The term “aryl” described herein means an organic radical derived from aromatic hydrocarbon via elimination of one hydrogen atom. Each ring suitably comprises a monocyclic or fused ring system containing from 4 to 7, preferably from 5 to 6 cyclic atoms. Specific examples include phenyl, naphthyl, biphenyl, anthryl, indenyl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, perylenyl, chrysenyl, naphthacenyl and fluoranthenyl, but they are not restricted thereto.
The term “heteroaryl” described herein means an aryl group containing from 1 to 4 heteroatom(s) selected from N, O and S for the aromatic cyclic backbone atoms, and carbon atom(s) for remaining aromatic cyclic backbone atoms. The heteroaryl may be 5- or 6-membered monocyclic heteroaryl or a polycyclic heteroaryl which is fused with one or more benzene ring(s), and may be partially saturated. The heteroaryl groups include bivalent aryl group of which the heteroatom in the ring is oxidized or quarternized to form an N-oxide or a quaternary salt. Specific examples include monocyclic heteroaryl groups such as furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl; and polycyclic heteroaryl groups such as benzofuranyl, benzothiophenyl, isobenzofuranyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzisoxazolyl, benzoxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinolizinyl, quinoxalinyl, carbazolyl, phenanthridinyl and benzodioxolyl; and corresponding N-oxides (for example, pyridyl N-oxide, quinolyl N-oxide) or quaternary salt thereof, but they are not restricted thereto.
The substituents comprising “(C1-C60)alkyl” moiety described herein may contain 1 to 60 carbon atoms, 1 to 20 carbon atoms, or 1 to 10 carbon atoms. The substituents comprising “(C6-C60)aryl” moiety may contain 6 to 60 carbon atoms, 6 to 20 carbon atoms, or 6 to 12 carbon atoms. The substituents comprising “(C3-C60)heteroaryl” moiety may contain 3 to 60 carbon atoms, 4 to 20 carbon atoms, or 4 to 12 carbon atoms. The substituents comprising “(C3-C60)cycloalkyl” moiety may contain 3 to 60 carbon atoms, 3 to 20 carbon atoms, or 3 to 7 carbon atoms. The substituents comprising “(C2-C60)alkenyl or alkynyl” moiety may contain 2 to 60 carbon atoms, 2 to 20 carbon atoms, or 2 to 10 carbon atoms.
The organic electroluminescent compounds according to the present invention may be selected from the compounds represented by one of Chemical Formulas (2) to (4):
wherein, A, B, Ar1, Ar2, R1 through R20, X1, X2, Y1, Y2, m and n are defined as in Chemical Formula (1).
In Chemical Formula (1), L1 is selected from the following structures, but not restricted thereto:
wherein, R15 through R20 independently represent hydrogen, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, i-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, decyl, dodecyl, hexadecyl, benzyl, trifluoromethyl, perfluoroethyl, trifluoroethyl, perfluoropropyl, perfluorobutyl, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, t-butoxy, n-pentoxy, i-pentoxy, n-hexyloxy, n-heptoxy, trimethylsilyl, triethylsilyl, tripropylsilyl, tri(t-butyl)silyl, t-butyldimethylsilyl, dimethylphenylsilyl, triphenylsilyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, phenyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, phenanthryl, anthryl, fluoranthenyl, triphenylenyl, pyrenyl, chrysenyl, naphthacenyl, perylenyl, morpholino, thiomorpholino, adamantyl, bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl, bicyclo[3.2.1]octyl, bicyclo[5.2.0]nonyl, bicyclo[4.2.2]decyl, bicyclo[2.2.2]octyl, 4-pentylbicyclo[2.2.2]octyl, ethenyl, phenylethenyl, ethynyl, phenylethynyl, cyano, dimethylamino, diphenylamino, monomethylamino, monophenylamino, phenyloxy, phenylthio, methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, carboxyl, nitro, chloro, fluoro or hydroxyl.
In the formulas,
and
independently represent a chemical bond, or a structure selected, without restriction, from the followings:
wherein, R51 through R56 independently represent methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, i-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, decyl, dodecyl, hexadecyl, benzyl, phenyl, naphthyl or anthryl.
In the formulas,
are selected from the following structures, but not restricted thereto:
wherein, R31 through R36 independently represent (C1-C60)alkyl, (C6-C60)aryl or (C3-C60)heteroaryl, or R31 and R32 or R34 and R35 may be linked via (C3-C60)alkylene or (C3-C60)alkenylene with or without a fused ring to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring; and the alkyl, aryl or heteroaryl of R31 through R36 may be further substituted by one or more substituent(s) selected from halogen, (C1-C60)alkyl with or without halogen substituent(s), (C6-C60)aryl, (C3-C60)heteroaryl with or without (C6-C60)aryl substituent(s), 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C1-C60)alkoxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro and hydroxyl;
provided that if both
represent
R33 does not represent (C1-C5)alkyl.
The organic electroluminescent compounds according to the present invention can be more specifically exemplified by the following compounds, but they are not restricted thereto.
The organic electroluminescent compounds according to the present invention can be prepared, for example, as illustrated by Reaction Scheme (1), without restriction.
Further, the present invention provides organic solar cells, which comprise one or more organic electroluminescent compound(s) represented by Chemical Formula (1).
The present invention also provides an organic electroluminescent device which is comprised of a first electrode; a second electrode; and at least one organic layer(s) interposed between the first electrode and the second electrode; wherein the organic layer comprises one or more organic electroluminescent compound(s) represented by Chemical Formula (1).
The organic electroluminescent device according to the present invention is characterized in that the organic layer comprises an electroluminescent layer, which contains one or more organic electroluminescent compound(s) represented by Chemical Formula (1) as electroluminescent dopant, and one or more host(s). The host to be applied to an organic electroluminescent device according to the present invention is not particularly restrictive, but preferably selected from the compounds represented by Chemical Formula (5) or (6):
(Ar10)a—X—(Ar20)b Chemical Formula 5
(Ar30)c—Y—(Ar40)d Chemical Formula 6
wherein, x represents (C6-C60)arylene or (C4-C60)heteroarylene;
Y represents anthracenylene;
Ar10 through Ar40 are independently selected from hydrogen, (C1-C60)alkyl, (C1-C60)alkoxy, halogen, (C4-C60)heteroaryl, (C5-C60)cycloalkyl and (C6-C60)aryl; the cycloalkyl, aryl or heteroaryl of Ar10 through Ar40 may be further substituted by one or more substituent(s) selected from a group consisting of (C6-C60)aryl or (C4-C60)heteroaryl with or without one or more substituent(s) selected from a group consisting of (C1-C60)alkyl with or without halogen substituent(s), (C1-C60)alkoxy, (C3-C60)cycloalkyl, halogen, cyano, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl and tri(C6-C60)arylsilyl; (C1-C60)alkyl with or without halogen substituent(s), (C1-C60)alkoxy, (C3-C60)cycloalkyl, halogen, cyano, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl and tri(C6-C60)arylsilyl; and
a, b, c and d independently represent an integer from 0 to 4.
The host of Chemical Formula (5) or (6) can be exemplified by anthracene derivatives and benz[a]anthracene derivatives represented by one of Chemical Formulas (7) to (9):
wherein, R101 and R102 independently represent hydrogen, (C1-C60)alkyl, halogen, (C6-C60)aryl, (C4-C60)heteroaryl, 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, or (C3-C60)cycloalkyl; the aryl or heteroaryl of R101 and R102 may be further substituted by one or more substituent(s) selected from a group consisting of (C1-C60)alkyl, halo(C1-C60)alkyl, (C1-C60)alkoxy, (C3-C60)cycloalkyl, (C6-C60)aryl, (C4-C60)heteroaryl, halogen, cyano, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl and tri(C6-C60)arylsilyl;
R103 through R106 independently represent hydrogen, (C1-C60)alkyl, (C1-C60)alkoxy, halogen, (C4-C60)heteroaryl, (C5-C60)cycloalkyl or (C6-C60)aryl; the heteroaryl, cycloalkyl or aryl of R63 through R66 may be further substituted by one or more substituent(s) selected from a group consisting of (C1-C60)alkyl with or without halogen substituent(s), (C1-C60)alkoxy, (C3-C60)cycloalkyl, halogen, cyano, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl and tri(C6-C60)arylsilyl;
Z1 and Z2 independently represent a chemical bond, or (C6-C60)arylene with or without one or more substituent(s) selected from (C1-C60)alkyl, (C1-C60)alkoxy, (C6-C60)aryl, (C4-C60)heteroaryl and halogen;
Ar11 and Ar12 independently represent aryl or (C4-C60)heteroaryl selected from the following structures;
the aryl or heteroaryl of Ar11 and Ar12 may be substituted by one or more substituent(s) selected from (C1-C60)alkyl, (C1-C60)alkoxy, (C6-C60)aryl and (C4-C60)heteroaryl;
L11 represents (C6-C60)arylene, (C4-C60)heteroarylene or a compound having the following structure;
the arylene or heteroarylene of L11 may be substituted by one or more substituent(s) selected from (C1-C60)alkyl, (C1-C60)alkoxy, (C6-C60)aryl, (C4-C60)heteroaryl and halogen;
R111, R112, R113 and R114 independently represent hydrogen, (C1-C60)alkyl or (C6-C60)aryl, or they may be linked to an adjacent substituent via (C3-C60)alkylene or (C3-C60)alkenylene with or without a fused ring to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring; and
R121, R122, R123 and R124 independently represent hydrogen, (C1-C60)alkyl, (C1-C60)alkoxy, (C6-C60)aryl, (C4-C60)heteroaryl or halogen, or they may be linked to an adjacent substituent via (C3-C60)alkylene or (C3-C60)alkenylene with or without a fused ring to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring.
The electroluminescent layer means the layer where electroluminescence occurs, and it may be a single layer or a multi-layer consisting of two or more layers laminated. When a mixture of host-dopant is used according to the constitution of the present invention, noticeable improvement in luminous efficiency by the electroluminescent host according to the invention could be confirmed. Those results can be achieved by doping concentration of 0.5 to 10% by weight. The host according to the present invention exhibits higher hole and electron conductivity, and excellent stability of the material as compared to other conventional host materials, and provides improved device life as well as luminous efficiency.
Thus, it can be described that use of the compound represented by one of Chemical Formulas (7) to (9) as an electroluminescent host significantly supplements electronic drawback of the organic electroluminescent compounds of Chemical Formula (1) according to the present invention. The host compounds represented by one of Chemical Formulas (7) to (9) can be exemplified by the following compounds, but are not restricted thereto.
The organic electroluminescent device according to the present invention may further comprise one or more compound(s) selected from a group consisting of arylamine compounds and styrylarylamine compounds, as well as the organic electroluminescent compound represented by Chemical Formula (1). Examples of the arylamine or styrylarylamine compounds include the compounds represented by Chemical Formula (10), but they are not restricted thereto:
wherein, Ar21 and Ar22 independently represent (C1-C60)alkyl, (C6-C60)aryl, (C4-C60)heteroaryl, (C6-C60)arylamino, (C1-C60)alkylamino, morpholino or thiomorpholino, 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, or (C3-C60)cycloalkyl, or Ar21 and Ar22 may be linked via (C3-C60)alkylene or (C3-C60)alkenylene with or without a fused ring to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring; the aryl, heteroaryl, arylamino or heterocycloalkyl of Ar21 and Ar22 may be further substituted by one or more substituent(s) selected from halogen, (C1-C60)alkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C6-C60)aryl, (C4-C60)heteroaryl, 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C1-C60)alkyloxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro and hydroxyl;
Ar23 represents (C6-C60)aryl, (C5-C60)heteroaryl or (C6-C60)arylamino; the aryl, heteroaryl or arylamino of Ar23 may be further substituted by one or more substituent(s) selected from halogen, (C1-C60)alkyl, (C6-C60)aryl, (C4-C60)heteroaryl, 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C1-C60)alkoxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro and hydroxyl; and
g is an integer from 1 to 4.
The arylamine compounds or styrylarylamine compounds can be more specifically exemplified by the following compounds, but they are not restricted thereto.
In an organic electroluminescent device according to the present invention, the organic layer may further comprise one or more metal(s) selected from a group consisting of organic metals of Group 1, Group 2, 4th period and 5th period transition metals, lanthanide metals and d-transition elements, as well as the organic electroluminescent compound represented by Chemical Formula (1). The organic layer may comprise a charge generating layer in addition to the electroluminescent layer.
The present invention can realize an organic electroluminescent device having a pixel structure of independent light-emitting mode, which comprises an organic electroluminescent device containing the compound of Chemical Formula (1) as a sub-pixel and one or more sub-pixel(s) comprising one or more metallic compound(s) selected from a group consisting of Ir, Pt, Pd, Rh, Re, Os, Tl, Pb, Bi, In, Sn, Sb, Te, Au and Ag, patterned in parallel at the same time.
Further, the organic electroluminescent device is an organic electroluminescent display wherein the organic layer comprises, in addition to the organic electroluminescent compound represented by Chemical Formula (1), one or more compound(s) selected from compounds having an electroluminescent peak at the wavelength of 480 to 560 nm, or those having an electroluminescent peak at the wavelength of 560 nm or more, at the same time. The compounds having an electroluminescent peak at the wavelength of 480 to 560 nm, or those having an electroluminescent peak at the wavelength of 560 nm or more may be exemplified by the compounds represented by one of Chemical Formulas (11) to (17), but they are not restricted thereto.
M1L21L22L23 Chemical Formula 11
In Chemical Formula (11), M1 is selected from metals from Group 7, 8, 9, 10, 11, 13, 14, 15 and 16 in the Periodic Table of Elements, and ligands L21, L22 and L23 are independently selected from the following structures:
wherein, R201 through R203 independently represent hydrogen, (C1-C60)alkyl with or without halogen substituent(s), (C6-C60)aryl with or without (C1-C60)alkyl substituent(s), or halogen;
R204 through R219 independently represent hydrogen, (C1-C60)alkyl, (C1-C30)alkoxy, (C3-C60)cycloalkyl, (C2-C30)alkenyl, (C6-C60)aryl, mono or di(C1-C30)alkylamino, mono or di(C6-30)arylamino, SF5, tri(C1-C30)alkylsilyl, di(C1-C30)alkyl(C6-C30)arylsilyl, tri(C6-C30)arylsilyl, cyano or halogen, and the alkyl, cycloalkyl, alkenyl or aryl of R204 through R219 may be further substituted by one or more substituent(s) selected from (C1-C60)alkyl, (C6-C60)aryl and halogen;
R220 through R223 independently represent hydrogen, (C1-C60)alkyl with or without halogen substituent(s), (C6-C60)aryl with or without (C1-C60)alkyl substituent(s);
R224 and R225 independently represent hydrogen, linear or branched (C1-C60)alkyl, (C6-C60)aryl or halogen, or R224 and R225 may be linked via (C3-C12)alkylene or (C3-C12)alkenylene with or without a fused ring to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring; the alkyl or aryl of R224 and R225, or the alicyclic ring, or the monocyclic or polycyclic aromatic ring formed therefrom via (C3-C12)alkylene or (C3-C12)alkenylene with or without a fused ring may be further substituted by one or more substituent(s) selected from linear or branched (C1-C60)alkyl with or without halogen substituent(s), (C1-C30)alkoxy, halogen, tri(C1-C30)alkylsilyl, tri(C6-C30)arylsilyl and (C6-C60)aryl;
R226 represents (C1-C60)alkyl, (C6-C60)aryl, (C5-C60)heteroaryl or halogen;
R227 through R229 independently represent hydrogen, (C1-C60)alkyl, (C6-C60)aryl or halogen; the alkyl or aryl of R226 through R229 may be further substituted by halogen or (C1-C60)alkyl;
Q represents
and R231 through R242 independently represent hydrogen, (C1-C60)alkyl with or without halogen substituent(s), (C1-C30)alkoxy, halogen, (C6-C60)aryl, cyano or (C5-C60)cycloalkyl, or each of R231 through R242 may be linked to an adjacent substituent via alkylene or alkenylene to form a (C5-C7) spiro-ring or a (C5-C9) fused ring, or each of them may be linked to R207 or R208 via alkylene or alkenylene to form a (C5-C7) fused ring.
In Chemical Formula (12), R301 through R304 independently represent (C1-C60)alkyl or (C6-C60)aryl, or each of them may be linked to an adjacent substituent via (C3-C60)alkylene or (C3-C60)alkenylene with or without a fused ring to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring; and the alkyl or aryl of R301 through R304, or the alicyclic ring, or the monocyclic or polycyclic aromatic ring formed therefrom by linkage via (C3-C60)alkylene or (C3-C60)alkenylene with or without a fused ring may be further substituted by one or more substituent(s) selected from (C1-C60)alkyl with or without halogen substituent(s), (C1-C60)alkoxy, halogen, tri(C1-C60)alkylsilyl, tri(C6-C60)arylsilyl and (C6-C60)aryl.
L24L25M2(T)h Chemical Formula 15
In Chemical Formula (15), the ligands, L24 and L25 are independently selected from the following structures:
M2 is a bivalent or trivalent metal;
h is 0 when M2 is a bivalent metal, while h is 1 when M2 is a trivalent metal;
T represents (C6-C60)aryloxy or tri(C6-C60)arylsilyl, and the aryloxy and triarylsilyl of T may be further substituted by (C1-C60)alkyl or (C6-C60)aryl;
G represents O, S or Se;
ring C represents oxazole, thiazole, imidazole, oxadiazole, thiadiazole, benzoxazole, benzothiazole, benzimidazole, pyridine or quinoline;
ring D represents pyridine or quinoline, and ring B may be further substituted by (C1-C60)alkyl, or phenyl or naphthyl with or without (C1-C60)alkyl substituent(s);
R401 through R404 independently represent hydrogen, (C1-C60)alkyl, halogen, tri(C1-C60)alkylsilyl, tri(C6-C60)arylsilyl or (C6-C60)aryl, or each of them may be linked to an adjacent substituent via (C3-C60)alkylene or (C3-C60)alkenylene to form a fused ring; the pyridine or quinoline may form a chemical bond with R401 to form a fused ring; and
ring C or the aryl group of R401 through R404 may be further substituted by (C1-C60)alkyl, halogen, (C1-C60)alkyl with halogen substituent(s), phenyl, naphthyl, tri(C1-C60)alkylsilyl, tri(C6-C60)arylsilyl or amino group.
In Chemical Formula (16), Ar41 and Ar42 independently represent (C1-C60)alkyl, (C6-C60)aryl, (C4-C60)heteroaryl, (C6-C60)arylamino, (C1-C60)alkylamino, 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, or (C3-C60)cycloalkyl, or Ar41 and Ar42 may be linked via (C3-C60)alkylene or (C3-C60)alkenylene with or without a fused ring to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring; the alkyl, aryl, heteroaryl, arylamino, alkylamino, cycloalkyl or heterocycloalkyl of Ar41 and Ar42 may be further substituted by one or more substituent(s) selected from halogen, (C1-C60)alkyl, (C6-C60)aryl, (C4-C60)heteroaryl, 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C1-C60)alkoxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro and hydroxyl;
Ar43 represents (C6-C60)arylene, (C4-C60)heteroarylene or arylene represented by one of the following structural formulas:
wherein, Ar51 represents (C6-C60)arylene or (C4-C60)heteroarylene,
the arylene or heteroarylene of Ar43 and Ar51 may be further substituted by one or more substituent(s) selected from a group consisting of halogen, (C1-C60)alkyl, (C6-C60)aryl, (C4-C60)heteroaryl, 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C1-C60)alkyloxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro and hydroxyl;
i is an integer from 1 to 4;
j is an integer from 1 to 4; and
k is an integer of 0 or 1.
In Chemical Formula (17), R501 through R504 independently represent hydrogen, halogen, (C1-C60)alkyl, (C6-C60)aryl, (C4-C60)heteroaryl, a 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C1-C60)alkoxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro or hydroxyl, or each of R501 through R504 may be linked to an adjacent substituent via (C3-C60)alkylene or (C3-C60)alkenylene with or without a fused ring to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring; and
the alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, arylsilyl, alkylsilyl, alkylamino or arylamino of R501 through R504, or the alicyclic ring, or the monocyclic or polycyclic aromatic ring formed therefrom by linkage to an adjacent substituent via (C3-C60)alkylene or (C3-C60)alkenylene with or without a fused ring may be further substituted by one or more substituent(s) selected from halogen, (C1-C60)alkyl, (C6-C60)aryl, (C4-C60)heteroaryl, a 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, (C3-C60)cycloalkyl, tri(C1-C60)alkylsilyl, di(C1-C60)alkyl(C6-C60)arylsilyl, tri(C6-C60)arylsilyl, adamantyl, (C7-C60)bicycloalkyl, (C2-C60)alkenyl, (C2-C60)alkynyl, (C1-C60)alkoxy, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, carboxyl, nitro and hydroxyl.
The compounds having an electroluminescent peak at the wavelength of 480 to 560 nm and a compound having an electroluminescent peak at the wavelength longer than 560 nm, can be exemplified by the following compounds, but they are not restricted thereto.
In an organic electroluminescent device according to the present invention, it is preferable to arrange one or more layer(s) (here-in-below, referred to as the “surface layer”) selected from chalcogenide layers, metal halide layers and metal oxide layers, on the inner surface of at least one side of the pair of electrodes. Specifically, it is preferable to arrange a chalcogenide layer of silicon and aluminum metal (including oxides) on the anode surface of the EL medium layer, and a metal halide layer or a metal oxide layer on the cathode surface of the EL medium layer. As the result, stability in operation can be obtained.
Examples of chalcogenides preferably include SiOx (1≦X≦2), AlOx (1≦X≦1.5), SiON, SiAlON, or the like. Examples of metal halides preferably include LiF, MgF2, CaF2, fluorides of rare earth metal or the like. Examples of metal oxides preferably include Cs2O, Li2O, MgO, SrO, BaO, CaO, or the like.
In an organic electroluminescent device according to the present invention, it is also preferable to arrange, on at least one surface of the pair of electrodes thus manufactured, a mixed region of electron transport compound and a reductive dopant, or a mixed region of a hole transport compound with an oxidative dopant. Accordingly, the electron transport compound is reduced to an anion, so that injection and transportation of electrons from the mixed region to an EL medium are facilitated. In addition, since the hole transport compound is oxidized to form a cation, injection and transportation of holes from the mixed region to an EL medium are facilitated. Preferable oxidative dopants include various Lewis acids and acceptor compounds. Preferable reductive dopants include alkali metals, alkali metal compounds, alkaline earth metals, rare-earth metals, and mixtures thereof.
The organic electroluminescent compounds according to the present invention exhibit high luminous efficiency and excellent life property of material, so that an OLED having very good operation life can be manufactured therefrom.
The present invention is further described by referring to representative compounds with regard to the organic electroluminescent compounds according to the invention, preparation thereof and luminescent properties of the devices manufactured therefrom, but those examples are provided for illustration of the embodiments only, not being intended to limit the scope of the invention by any means.
Preparation of Compound (A)
A reaction vessel was charged with 2,7-dibromofluorene (30.2 g, 100 mmol) and potassium hydroxide (45 g, 80 mmol). After drying under reduced pressure, the vessel was filled with nitrogen gas. Dimethylsulfoxide (550 mL) was added thereto, and the resultant mixture was stirred for 30 minutes. After 30 minutes, water was added thereto in a double water boiler. Iodomethane (57 g, 400 mmol) was slowly added, and the mixture was stirred for 14 hours. The reaction mixture was washed with water (300 mL), and extracted with dichloromethane (300 mL). The extract was dried over anhydrous magnesium sulfate, filtered and concentrated. Recrystallization from methanol (500 mL) gave the target compound (Compound A) (30 g, 85.21 mmol).
Preparation of Compound (B)
Compound (A) (20.0 g, 56.81 mmol) thus obtained was dissolved in tetrahydrofuran (1000 mL), and the solution was chilled to −78° C. Then 2.5 M butyllithium (n-BuLi) (56.81 mL, 142.02 mmol) was slowly added dropwise thereto. After stirring for 30 minutes, N,N-dimethylformamide (DMF) (13.19 mL, 170.43 mmol) was added thereto. The mixture was stirred for 2 hours while slowly raising the temperature and the reaction was quenched by adding aqueous NH4Cl solution (800 mL) and distilled water (800 mL). The organic layer was separated and evaporated under reduced pressure. Recrystallization from methanol and hexane gave Compound (B) (11.09 g, 44.31 mmol).
Preparation of Compound (C)
A reaction vessel was charged with Compound (B) (11.09 g, 44.31 mmol) and NaBH4 (2.5 g, 66.47 mmol). After removing the air under reduced pressure, the vessel was filled with nitrogen gas. Tetrahydrofuran solvent (600 mL) was added thereto, and the resultant mixture was stirred. While stirring, methanol (350 mL) was slowly added dropwise. When the reaction was completed, the reaction mixture was washed with water (1000 mL), and extracted with ethyl acetate. Purification via column chromatography by using dichloromethane and hexane gave the target compound (Compound C) (8.45 g, 33.12 mmol).
Preparation of Compound (D)
A reaction vessel was charged with Compound (C) (5.0 g, 19.66 mmol). After removing air therein under reduced pressure, the vessel was filled with nitrogen gas. Then 5 mL portion of triethylphosphite (10.15 mL, 58.98 mmol) was added thereto to obtain complete dissolution. Another reaction vessel was charged with remaining triethylphosphite (5.15 mL), which was stirred at 0° C. for 30 minutes while slowly adding I2 (9.98 g, 39.32 mmol) with the lid open. The mixture of iodine and triethylphosphite was added to the reaction vessel containing Compound (C). The resultant mixture was heated to 150° C., and stirred for 4 hours. When the reaction was completed, triethylphosphite was removed by distillation under reduced pressure. The residue was washed with water 50 mL, and extracted with ethyl acetate (50 mL). Recrystallization from methanol gave Compound (D) (13.59 g, 27.48 mmol).
Preparation of Compound (E)
A reaction vessel was charged with N,N-dimethylformamide (26.62 mL, 352.24 mmol). After drying under reduced pressure, the vessel was filled with nitrogen gas. Phosphorus oxychloride (16.09 mL, 172.62 mmol) was slowly added dropwise thereto at 0° C. Then the temperature was raised to 25° C., and stirring continued. After 2 hours, N-phenyl-carbazole (14.0 g, 57.54 mmol) was directly added in solid state. After 30 minutes, the mixture was heated and distilled at 90° C. with stirring for 18 hours. Then the reaction vessel was cooled to 25° C., and the reaction mixture was slowly added dropwise to concentrated sodium hydroxide solution in a bath at 0° C. to neutralize the mixture. The mixture was extracted with dichloromethane (300 mL), and the extract was dried over anhydrous magnesium sulfate, filtered and concentrated. Purification via column chromatography by using ethyl acetate and hexane gave the target compound (Compound E) (12.3 g, 45.34 mmol).
Preparation of Compound (154)
A reaction vessel was charged with Compound (D) (5.1 g, 9.72 mmol) and Compound (E) (5.8 g, 21.37 mmol), and dried under reduced pressure. Under nitrogen atmosphere, tetrahydrofuran solvent (200 mL) was added thereto, and the mixture stirred. Solution of potassium tert-butoxide (t-BuOK) (4.14 g, 37.17 mmol) dissolved in tetrahydrofuran (30 mL) was slowly added dropwise thereto at 0° C., and the temperature was slowly raised to ambient temperature. After stirring for 4 hours and the reaction was completed, water (500 mL) was poured thereto, and the solid produced was filtered. The solid was washed three times with methanol (1 L). Recrystallization from tetrahydrofuran and methanol and washing with hexane gave the target compound (Compound 154) (5.00 g, 6.6 mmol, yield: 68.0%).
The organic electroluminescent compounds (Compounds 1 to 725) were prepared according to the same procedure as in Preparation Example 1, of which 1H NMR and MS/FAB data are listed in Table 1.
1H NMR (CDCl3, 200 MHz)
An OLED device was manufactured by using an electroluminescent material according to the invention.
First, a transparent electrode ITO thin film (15 Ω/□) (2) prepared from glass for OLED (1) (manufactured by Samsung-Corning) was subjected to ultrasonic washing with trichloroethylene, acetone, ethanol and distilled water, sequentially, and stored in isopropanol before use.
Then, an ITO substrate was equipped in a substrate folder of a vacuum vapor-deposit device, and 4,4′,4″-tris(N,N-(2-naphthyl)-phenylamino)triphenylamine (2-TNATA) (of which the structure is shown below) was placed in a cell of the vacuum vapor-deposit device, which was then ventilated up to 10−6 torr of vacuum in the chamber. Electric current was applied to the cell to evaporate 2-TNATA, thereby providing vapor-deposit of a hole injecting layer (3) having 60 nm of thickness on the ITO substrate.
Then, to another cell of the vacuum vapor-deposit device, charged was N,N′-bis(α-naphthyl)-N,N′-diphenyl-4,4′-diamine (NPB) (of which the structure is shown below), and electric current was applied to the cell to evaporate NPB, thereby providing vapor-deposit of a hole transport layer (4) with 20 nm of thickness on the hole injecting layer.
After forming the hole injecting layer and the hole transport layer, an electroluminescent layer was vapor-deposited as follows. To one cell of a vacuum vapor-deposit device, charged was Compound H-28 (of which the structure is shown below) as a host, and a compound according to the invention (Compound 165) was charged to another cell as a dopant. The two substances were evaporated at different rates to give doping at 2 to 5% by weight on the basis of the host, thereby providing vapor-deposit of an electroluminescent layer (5) with a thickness of 30 nm on the hole transport layer.
Then, tris(8-hydroxyquinoline)aluminum (III) (Alq) (of which the structure is shown below) was vapor-deposited as an electron transport layer (6) with a thickness of 20 nm, and lithium quinolate (Liq) (of which the structure shown below) was vapor-deposited as an electron injecting layer (7) with a thickness of 1 to 2 nm. Thereafter, an Al cathode (8) was vapor-deposited with a thickness of 150 nm by using another vacuum vapor-deposit device to manufacture an OLED.
Each material employed for manufacturing an OLED was used as the electroluminescent material after purifying via vacuum sublimation at 10−6 torr.
After forming a hole injecting layer and a hole transport layer according to the same procedure as described in Example 1, dinaphthylanthracene (DNA) was charged to another cell of said vacuum vapor-deposit device as an electroluminescent host material, while Compound (A) (of which the structure is shown below) was charged to still another cell as blue electroluminescent material. An electroluminescent layer was vapor-deposited with a thickness of 30 nm on the hole transport layer, with vapor-deposition rate of 100:1.
Then, an electron transport layer and an electron injecting layer were vapor-deposited according to the same procedures as in Example 1, and Al cathode was vapor-deposited by using another vacuum vapor-deposit device with a thickness of 150 nm, to manufacture an OLED.
The luminous efficiencies of the OLED's comprising the organic electroluminescent compounds according to the present invention (Example 1) or conventional electroluminescent compound (Comparative Example 1) were measured at 1,000 cd/m2, respectively, and the results are shown in Table 2.
As can be seen from Table 2, the blue electroluminescent devices employing the material according to the present invention showed improved luminous efficiency as compared that of Comparative Example 1. Compound (H-66) with 3.0 wt % doping of Compound (389) showed the highest luminous efficiency.
Accordingly, the organic electroluminescent compounds according to the present invention can be used as blue electroluminescent material of high efficiency. Moreover, the device, to which the dopant material according to the invention was applied, showed noticeable improvement in view of color purity. The improvement in both color purity and luminous efficiency proves that the materials of the present invention have excellent properties.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2008-0060393 | Jun 2008 | KR | national |
