Patent Application
20090252990
The present invention relates to novel organic electroluminescent compounds exhibiting high luminous efficiency and organic electroluminescent devices comprising the same.
The most important factor to determine luminous efficiency in an OLED (organic light-emitting diode) is the type of electroluminescent material. Though fluorescent materials has been widely used as an electroluminescent material up to the present, development of phosphorescent materials is one of the best methods to improve the luminous efficiency theoretically up to four (4) times, in view of electroluminescent mechanism.
Up to now, iridium (III) complexes are widely known as phosphorescent material, including (acac)Ir(btp)2, Ir(ppy)3 and Firpic, as the red, green and blue one, respectively. In particular, a lot of phosphorescent materials have been recently investigated in Japan, Europe and America.
Among conventional red phosphorescent materials, several materials have been reported to have good EL (electroluminescence) properties. However, very rare materials among them have reached the level of commercialization. As the most preferable material, an iridium complex of 1-phenyl isoquinoline may be mentioned, which is known to have excellent EL property and to exhibit color purity of dark red with high luminous efficiency. [See A. Tsuboyama et al., J. Am. Chem. Soc. 2003, 125(42), 12971-12979.]
Moreover, the red materials, having no significant problem of lifetime, have tendency of easy commercialization if they have good color purity or luminous efficiency. Thus, the above-mentioned iridium complex is a material having noticeable viability of commercialization due to its excellent color purity and luminous efficiency.
However, the iridium complex is still construed as a material which is merely applicable to small displays, while higher levels of EL properties than those of known materials are practically required for an OLED panel of medium to large size.
With intensive efforts to overcome the problems of conventional techniques as described above, the present inventors have researched for developing novel organic electroluminescent compounds to realize an organic EL device having excellent luminous efficiency and surprisingly improved lifetime. Eventually, the inventors found that luminous efficiency and life property are improved when an iridium complex, which was synthesized by introducing phenyl derivatives at 3- and 4-position of quinoline in the primary ligand compound, is applied as a dopant of an electroluminescent device, and completed the present invention. Thus, the object of the invention is to provide novel organic electroluminescent compounds having the backbone to give more excellent properties as compared to those of conventional red phosphorescent materials. Another object of the invention is to provide novel organic electroluminescent compounds which are applicable to OLED panels of medium to large size.
Still another object of the invention is to provide organic electroluminescent devices and organic solar cells comprising the novel organic electroluminescent compounds.
Thus, the present invention relates to novel organic electroluminescent compounds and organic electroluminescent devices comprising the same. Specifically, the organic electroluminescent compounds according to the invention are characterized in that they are represented by Chemical Formula (1):
wherein, L is an organic ligand;
R1 through R4 independently represent hydrogen, (C1-C60)alkyl, (C1-C60)alkoxy, (C3-C60)cycloalkyl, halogen, tri(C1-C60)alkylsilyl or tri(C6-C60)arylsilyl;
R5 and R6 independently represent hydrogen, (C1-C60)alkyl, halogen or (C6-C60)aryl;
R7 and R8 independently represent hydrogen, (C1-C60)alkyl with or without halogen substituent(s), (C6-C60)aryl, halogen, cyano, tri(C1-C60)alkylsilyl, tri(C6-C60)arylsilyl, (C1-C60)alkoxy, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, di(C1-C60)alkylamino or di(C6-C60)arylamino, or R7 and R8 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 R7 and R8, or the alicyclic ring, or the monocyclic or polycyclic aromatic ring formed therefrom by linkage via (C3-C12) alkylene or (C3-C12)alkenylene may be further substituted by one or more substituent(s) selected from (C1-C60)alkyl, halogen, cyano, tri(C1-C60)alkylsilyl, tri(C6-C60)arylsilyl, (C1-C60)alkoxy, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, di(C1-C60)alkylamino, di(C6-C60)arylamino, phenyl, naphthyl, anthryl, fluorenyl, spirobifluorenyl and
and
n is an integer from 1 to 3.
Referring now to the Drawings,
The term “alkyl” described herein and any substituents comprising “alkyl” moiety 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 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, tetrahydronaphthyl, 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 as the aromatic cyclic backbone atom(s), and carbon atom(s) for remaining aromatic cyclic backbone atoms. The heteroaryl may be a 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 group may comprise a bivalent aryl group, of which the heteroatoms may be oxidized or quaternized to form N-oxide and 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; polycyclic heteroaryl groups such as benzofuranyl, benzothiophenyl, isobenzofuranyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzisoxazolyl, benzoxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, carbazolyl, phenanthridinyl and benzodioxolyl; and corresponding N-oxides (for example, pyridyl N-oxide, quinolyl N-oxide) and quaternary salts thereof; but they are not restricted thereto.
The naphthyl of Chemical Formula (1) may be 1-naphthyl or 2-naphthyl; the anthryl may be 1-anthryl, 2-anthryl or 9-anthryl; and the fluorenyl may be 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl or 9-fluorenyl.
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 alicyclic ring, or the monocyclic or polycyclic aromatic ring formed from R7 and R8 in Chemical Formula (1) by linkage via (C3-C12)alkylene or (C3-C12)alkenylene with or without a fused ring is benzene, naphthalene, anthracene, fluorene, indene or phenanthrene. The compound within the square bracket ([ ]) serves as a primary ligand of iridium, and L serves as a subsidiary ligand. The organic electroluminescent compounds according to the present invention also include the complex with the ratio of primary ligand:subsidiary ligand=2:1 (n=2) and the complex with the ratio of primary ligand:subsidiary ligand=1:2 (n=1), as well as the tris-chelated complexes without subsidiary ligand (L) (n=3).
The organic electroluminescent compounds according to the invention may be exemplified by the compounds represented by one of Chemical Formulas (2) to (7):
wherein, L, R1, R2, R3, R4, R5, R6, R7 and n are defined as in Chemical Formula (1);
R11 through R18 independently represent hydrogen, (C1-C60)alkyl, halogen, cyano, tri(C1-C60)alkylsilyl, tri(C6-C60)arylsilyl, (C1-C60)alkoxy, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, di(C1-C60)alkylamino, di(C6-C60)arylamino, phenyl, naphthyl, anthryl, fluorenyl, spirobifluorenyl or
the alkyl, phenyl, naphthyl, anthryl or fluorenyl of R11 through R18 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, (C1-C60)alkylcarbonyl, (C1-C60)arylcarbonyl, di(C1-C60)alkylamino, di(C6-C60)arylamino and (C6-C60)aryl;
R19 and R20 independently represent hydrogen, (C1-C60)alkyl or (C6-C60)aryl, or R19 and R20 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;
R21 represents (C1-C60)alkyl, halogen, cyano, tri(C1-C60)alkylsilyl, tri(C6-C60)arylsilyl, (C1-C60)alkoxy, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, phenyl, di(C1-C60)alkylamino, di(C6-C60)arylamino, naphthyl, 9,9-di(C1-C60)alkylfluorenyl or 9,9-di(C6-C60)arylfluorenyl; and
m is an integer from 1 to 5.
Preferably, R11 through R18 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, trifluoromethyl, fluoro, cyano, trimethylsilyl, tripropylsilyl, tri(t-butyl)silyl, t-butyldimethylsilyl, triphenylsilyl, methoxy, ethoxy, butoxy, methylcarbonyl, ethylcarbonyl, t-butylcarbonyl, phenylcarbonyl, dimethylamino, diphenylamino, phenyl, naphthyl, anthryl, fluorenyl or
and the fluorenyl may be further substituted by 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, phenyl, naphthyl, anthryl, trimethylsilyl, tripropylsilyl, tri(t-butyl)silyl, t-butyldimethylsilyl or triphenylsilyl.
It is preferable that R1 through R4 of Chemical Formula (1) 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, ethylhexyl, methoxy, ethoxy, butoxy, cyclopropyl, cyclohexyl, cycloheptyl, fluoro, trimethylsilyl, tripropylsilyl, tri(t-butyl)silyl, t-butyldimethylsilyl or triphenylsilyl; and R6 represents hydrogen, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, i-pentyl, n-hexyl, n-heptyl, n-octyl, ethylhexyl, fluoro, phenyl, naphthyl, anthryl, fluorenyl or spirobifluorenyl.
The organic electroluminescent compounds according to the present invention can be specifically exemplified by the following compounds, but they are not restricted thereto:
wherein, L represents an organic ligand;
R5 and R6 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, ethylhexyl, fluoro, phenyl or naphthyl;
R51 and R52 independently represent methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, i-pentyl, n-hexyl, n-heptyl, n-octyl, ethylhexyl, phenyl or naphthyl, or R51 and R52 may be linked each other via (C3-C12)alkylene or (C3-C12)alkenylene with or without a fused fing to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring;
R53 represents 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, trimethylsilyl, tripropylsilyl, tri(t-butyl)silyl, t-butyldimethylsilyl, triphenylsilyl, phenyl or naphthyl;
m is an integer from 1 to 5; and
n is an integer from 1 to 3.
The subsidiary ligands (L) of the organic electroluminescent compounds according to the present invention include the following structures:
wherein, R31 and R32 independently represent hydrogen, (C1-C60)alkyl with or without halogen substituent(s), phenyl with or without (C1-C60)alkyl substituent(s), or halogen;
R33 through R39 independently represent hydrogen, (C1-C60)alkyl, phenyl with or without (C1-C60)alkyl substituent(s), tri(C1-C60)alkylsilyl or halogen;
R40 through R43 independently represent hydrogen, (C1-C60)alkyl, phenyl with or without (C1-C60)alkyl substituent(s); and
R44 represents (C1-C60)alkyl, phenyl with or without (C1-C60)alkyl substituent(s), or halogen.
The subsidiary ligands (L) of the organic electroluminescent compounds according to the present invention can be exemplified by the following structures, but they are not restricted thereto:
The processes for preparing the organic electroluminescent compounds according to the present invention are described by referring to Reaction Schemes (1) to (3) shown below:
wherein, R1, R2, R3, R4, R5, R6, R7, R8 and L are defined as in Chemical Formula (1).
Reaction Scheme (1) provides a compound of Chemical Formula (1) with n=1, in which iridium trichloride (IrCl3) and subsidiary ligand compound (L-H) are mixed in a solvent at a molar ratio of 1:2˜3, and the mixture is heated under reflux before isolating diiridium dimer. In the reaction stage, preferable solvent is alcohol or a mixed solvent of alcohol/water, such as 2-ethoxyethanol, and 2-ethoxyethanol/water mixtures. The isolated diiridium dimer is then heated with a primary ligand compound in organic solvent to provide an organic phosphorescent iridium compound having the ratio of primary ligand:subsidiary ligand of 1:2 as the final product. The reaction is carried out with AgCF3SO3, Na2CO3 or NaOH being admixed with organic solvent such as 2-ethoxyethanol and 2-methoxyethylether.
Reaction Scheme (2) provides a compound of Chemical Formula (1) with n=2, in which iridium trichloride (IrCl3) and a primary ligand compound are mixed in a solvent at a molar ratio of 1:2˜3, and the mixture is heated under reflux before isolating diiridium dimer. In the reaction stage, preferable solvent is alcohol or a mixed solvent of alcohol/water, such as 2-ethoxyethanol, and 2-ethoxyethanol/water mixtures. The isolated diiridium dimer is then heated with the subsidiary ligand compound (L-H) in organic solvent to provide an organic phosphorescent iridium compound having the ratio of primary ligand:subsidiary ligand of 2:1 as the final product. The molar ratio of the primary ligand compound and the subsidiary ligand (L) in the final product is determined by appropriate molar ratio of the reactant depending on the composition. The reaction may be carried out with AgCF3SO3, Na2CO3 or NaOH being admixed with organic solvent such as 2-ethoxyethanol, 2-methoxyethylether and 1,2-dichloroethane.
Reaction Scheme (3) provides a compound of Chemical Formula (1) with n=3, in which iridium complex prepared according to Reaction Scheme (2) and the primary ligand compound are mixed in glycerol at a molar ratio of 1:2˜3, and the mixture is heated under reflux to obtain organic phosphorescent iridium complex coordinated with three primary ligands.
The compounds employed as a primary ligand in the present invention can be prepared according to Reaction Scheme (4), on the basis of conventional processes, but it is not restrictive:
wherein, R1 through R8 are defined as in Chemical Formula (1).
The present invention also provides organic solar cells, which comprises 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 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 region, which comprises one or more organic electroluminescent compound(s) represented by Chemical Formula (1) as electroluminescent dopant in an amount of 0.01 to 10% by weight, and one or more host(s). The host applied to the organic electroluminescent device according to the invention is not particularly restricted, but may be exemplified by 1,3,5-tricarbazolylbenzene, polyvinylcarbazole, m-biscarbazolylphenyl, 4,4′4″-tri(N-carbazolyl)triphenylamine, 1,3,5-tri(2-carbazolylphenyl)benzene, 1,3,5-tris(2-carbazolyl-5-methoxyphenyl)benzene, bis(4-carbazolylphenyl)silane or the compounds represented by one of Chemical Formulas (8) to (11):
In Chemical Formula (8), R91 through R94 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, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C1-C60)alkyloxy, (C1-C60)alkylthio, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, carboxyl, nitro or hydroxyl, or each of R91 through R94 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 alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, arylsilyl, alkylsilyl, alkylamino, or arylamino of R91 through R94, 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, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C1-C60)alkyloxy, (C1-C60)alkylthio, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, carboxyl, nitro and hydroxyl.
In Chemical Formula (11), the ligands, L1 and L2 are independently selected from the following structures:
M1 is a bivalent or trivalent metal;
y is 0 when M1 is a bivalent metal, while y is 1 when M1 is a trivalent metal;
Q represents (C6-C60)aryloxy or tri(C6-C60)arylsilyl, and the aryloxy and triarylsilyl of Q may be further substituted by (C1-C60)alkyl or (C6-C60)aryl;
X represents O, S or Se;
ring A represents oxazole, thiazole, imidazole, oxadiazole, thiadiazole, benzoxazole, benzothiazole, benzimidazole, pyridine or quinoline;
ring B 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);
R101 through R104 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, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C1-C60)alkyloxy, (C1-C60)alkylthio, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, carboxyl, nitro or hydroxyl, or each of R10 through R104 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 pyridine or quinoline may form a chemical bond with R10, to form a fused ring;
the alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, arylsilyl, alkylsilyl, alkylamino, or arylamino of ring A and R101 through R104, 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, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C1-C60)alkyloxy, (C1-C60)alkylthio, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, carboxyl, nitro and hydroxyl.
The ligands, L1 and L2 are independently selected from the following structures:
wherein, X represents O, S or Se;
R101 through R104 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, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C1-C60)alkyloxy, (C1-C60)alkylthio, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, carboxyl, nitro or hydroxyl, or each of R10, through R104 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;
R111 through R116 and R121 through R139 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, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C1-C60)alkyloxy, (C1-C60)alkylthio, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, carboxyl, nitro or hydroxyl, or each of R111 through R116 and R121 through R139 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 alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, arylsilyl, alkylsilyl, alkylamino or arylamino of R10l through R104, R111 through R116, and R121 through R139, 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, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C1-C60)alkyloxy, (C1-C60)alkylthio, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, carboxyl, nitro and hydroxyl.
In Chemical Formula (11), M1 is a bivalent metal selected from Be, Zn, Mg, Cu and Ni, or a trivalent metal selected from Al, Ga, In and B, and Q is selected from the following structures.
The compounds of Chemical Formula (8) may be specifically exemplified by the compounds represented by the following structures, but they are not restricted thereto.
The compounds represented by one of Chemical Formulas (9) to (11) may be specifically exemplified by the compounds with one of the following structures, but they are not restricted thereto.
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 construction of the present invention, noticeable improvement in device life as well as in luminous efficiency could be confirmed.
The organic electroluminescent device according to the invention may further comprise one or more compound(s) selected from arylamine compounds and styrylarylamine compounds, as well as the organic electroluminescent compound represented by Chemical Formula (1). Examples of arylamine or styrylarylamine compounds include the compounds represented by Chemical Formula (12), but they are not restricted thereto:
wherein, Ar11 and Ar12 independently represent (C1-C60)alkyl, (C6-C60)aryl, (C4-C60)heteroaryl, (C6-C60)arylamino, (C1-C60)alkylamino, a 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, or (C3-C60)cycloalkyl, or Ar11 and Ar12 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;
when g is 1, Ar13 represents (C6-C60)aryl, (C4-C60)heteroaryl, or an aryl represented by one of the following structural formulas:
when g is 2, Ar13 represents (C6-C60)arylene, (C4-C60)heteroarylene, or an arylene represented by one of the following structural formulas:
wherein Ar21 and Ar22 independently represent (C6-C60)arylene or (C4-C60)heteroarylene;
R151, R152 and R153 independently represent hydrogen, (C1-C60)alkyl or (C6-C60)aryl;
t is an integer from 1 to 4, w is an integer of 0 or 1; and
the alkyl, aryl, heteroaryl, arylamino, alkylamino, cycloalkyl or heterocycloalkyl of Ar11 and Ar12, or the aryl, heteroaryl, arylene or heteroarylene of Ar13, or the arylene or heteroarylene of Ar21 and Ar22, or the alkyl or aryl of R151 through R153 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, 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, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C1-C60)alkyloxy, (C6-C60)arylthio, (C1-C60)alkylthio, (C1-C60)alkoxycarbonyl, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, carboxyl, nitro and hydroxyl.
The arylamine compounds and styrylarylamine compounds may be more specifically exemplified by the following compounds, but 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 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 compound(s) selected from a group consisting of arylamine compounds and styrylarylamine compounds, patterned in parallel at the same time.
Further, the organic electroluminescent device is an organic display which comprises one or more compound(s) selected from compounds having electroluminescent peak of wavelength of blue or green, at the same time. The compounds having electroluminescent peak of wavelength of blue or green may be exemplified by the compounds represented by one of Chemical Formulas (13) to (17), but they are not restricted thereto.
In Chemical Formula (14), Ar101 and Ar102 independently represent (C1-C60)alkyl, (C6-C60)aryl, (C4-C60)heteroaryl, (C6-C60)arylamino, (C1-C60)alkylamino, a 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, or (C3-C60)cycloalkyl, or Ar101 and Ar102 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;
when h is 1, Ar103 represents (C6-C60)aryl, (C4-C60)heteroaryl, or an aryl represented by one of the following structural formulas:
when h is 2, Ar103 represents (C6-C60)arylene, (C4-C60)heteroarylene, or an arylene represented by one of the following structural formulas:
wherein Ar201 and Ar202 independently represent (C6-C60)arylene or (C4-C60)heteroarylene;
R161, R162 and R163 independently represent hydrogen, (C1-C60)alkyl or (C6-C60)aryl;
i is an integer from 1 to 4, j is an integer of 0 or 1; and
the alkyl, aryl, heteroaryl, arylamino, alkylamino, cycloalkyl or heterocycloalkyl of Ar101 and Ar102, or the aryl, heteroaryl, arylene or heteroarylene of Ar103, or the arylene or heteroarylene of Ar201 and Ar202, or the alkyl or aryl of R161 through R163 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, 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, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C6-C60)aryloxy, (C1-C60)alkyloxy, (C6-C60)arylthio, (C1-C60)alkylthio, (C1-C60)alkoxycarbonyl, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, carboxyl, nitro and hydroxyl.
In Chemical Formula (15), R301 through R304 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, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C1-C60)alkyloxy, (C1-C60)alkylthio, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, carboxyl, nitro or hydroxyl, or each of R301 through R304 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 alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, arylsilyl, alkylsilyl, alkylamino or arylamino of R301 through R304, 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, cyano, (C1-C60)alkylamino, (C6-C60)arylamino, (C6-C60)ar(C1-C60)alkyl, (C1-C60)alkyloxy, (C1-C60)alkylthio, (C6-C60)aryloxy, (C6-C60)arylthio, (C1-C60)alkoxycarbonyl, (C1-C60)alkylcarbonyl, (C6-C60)arylcarbonyl, carboxyl, nitro and hydroxyl.
Chemical Formula 16
(Ar301)p-L11-(Ar302)q
Chemical Formula 17
(Ar303)r-L12-(Ar304)s
In Chemical Formulas (16) and (17),
L11 represents (C6-C60)arylene or (C4-C60)heteroarylene;
L12 represents anthracenylene;
Ar301 through Ar304 are independently selected from hydrogen, (C1-C60)alkyl, (C1-C60)alkoxy, halogen, (C4-C60)heteroaryl, (C5-C60)cycloalkyl and (C6-C60)aryl, and the cycloalkyl, aryl or heteroaryl of Ar301 through Ar304 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 at least one substituent(s) selected from a group consisting of (C1-C60)alkyl, halo(C1-C60)alkyl, (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
p, q, r and s independently represent an integer from 0 to 4.
The compounds represented by Chemical Formula (16) or (17) may be exemplified by the derivatives represented by one of Chemical Formulas (18) through (21).
In Chemical Formulas (18) to (20), R311 and R312 independently represent (C6-C60)aryl, (C4-C60)heteroaryl or a 5- or 6-membered heterocycloalkyl containing one or more heteroatom(s) selected from N, O and S, or (C3-C60)cycloalkyl, and the aryl or heteroaryl of R311 and R312 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;
R313 through R316 independently represent hydrogen, (C1-C60)alkyl, (C1-C60)alkoxy, halogen, (C4-C60)heteroaryl, (C5-C60)cycloalkyl or (C6-C60)aryl, and the heteroaryl, cycloalkyl or aryl of R313 through R316 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;
G1 and G2 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;
Ar41 and Ar42 independently represent aryl selected from the following structures or (C4-C60)heteroaryl:
the aryl or heteroaryl of Ar41 and Ar42 may be substituted by one or more substituent(s) selected from (C1-C60)alkyl, (C1-C60)alkoxy, (C6-C60)aryl and (C4-C60)heteroaryl;
L31 represents (C6-C60)arylene, (C4-C60)heteroarylene or a compound represented by the following structure:
the arylene or heteroarylene of L31 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;
R321, R322, R323 and R324 independently represent hydrogen, (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;
R331, R332, R333 and R334 independently represent hydrogen, (C1-C60)alkyl, (C1-C60)alkoxy, (C6-C60)aryl, (C4-C60)heteroaryl or halogen, 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.
In Chemical Formula 21,
L41 and L42 independently represent a chemical bond, (C6-C60)arylene or (C3-C60)heteroarylene, and the arylene or heteroarylene of L41 and L42 may be further substituted by one or more substituent(s) selected from (C1-C60)alkykl, halogen, cyano, (C1-C60)alkoxy, (C3-C60)cycloalkyl, (C6-C60)aryl, (C3-C60)heteroaryl, tri(C1-C30)alkylsilyl, di(C1-C30)alkyl(C6-C30)arylsilyl and tri(C6-C30)arylsilyl;
R201 through R219 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 R201 through R219 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;
Ar51 represents (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, adamantyl, (C7-C60)bicycloalkyl, or a substituent selected from the following structures:
wherein, R220 through R232 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;
E1 and E2 independently represent a chemical bond, —(CR233R234)z—, —N(R235)—, —S—, —O—, —Si (R236)(R237)—, —P(R238)—, —C(═O)—, —B(R239)—, —In(R240)—, —Se—, —Ge(R241)(R242)—, —Sn(R243)(R244)—, —Ga(R245)— or —C(R246)═C(R247)—;
R233 through R247 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 R233 through R247 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 aryl, heteroaryl, heterocycloalkyl, adamantyl or bicycloalkyl of Ar51, or the alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, arylsilyl, alkylsilyl, alkylamino or arylamino of R201 through R232 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;
x is an integer from 1 to 4; and
z is an integer from 0 to 4.
The organic compounds and organometallic compounds with green or blue electroluminescence 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, it is preferable to displace 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 lanthanides 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 invention, having a backbone of more excellent EL properties and thermal stability than conventional phosphorescent materials, provide higher quantum efficiency and lower operation voltage as compared to conventional materials. Thus, if an organic electroluminescent compound according to the present invention is applied to an OLED panel, further enhanced results are anticipated in development of OLED's having medium to large size. If the compound is applied to an organic solar cell as a material of high efficiency, more excellent properties are anticipated as compared to conventional materials.
The present invention is further described with respect to the compounds according to the invention, the processes for preparing the same, and electroluminescent properties of devices manufactured therefrom by referring to the representative compounds of the invention, which are provided for illustration of the embodiments only but are not intended to limit the scope of the invention by any means.
Preparation of Compound (A)
In a reaction vessel, 2-aminobenzophenone (10.0 g, 50.7 mmol), 1-phenylacetophenone (9.0 g, 50.7 mmol), acetic acid (169 mL) and sulfuric acid (10 drops) were charged, and the mixture was stirred under reflux in the presence of argon atmosphere. When the reaction was completed, the reaction mixture was cooled to room temperature, and an excess amount of aqueous ammonium hydroxide was added thereto. The solid generated was filtered and washed with distilled water. The solid was purified via column chromatography to obtain Compound (A) (12.5 g, 69%).
Preparation of Compound (B)
Compound (A) (9.0 g, 25.2 mmol) and iridium chloride (3.4 g, 11.5 mmol) were dissolved in 2-ethoxyethanol (38 mL) and distilled water (13 mL), and the solution was stirred under reflux for 24 hours. When the reaction was completed, the reaction mixture was cooled to room temperature. The solid generated then was filtered and dried to obtain Compound (B) (6.9 g, 100%).
Preparation of Compound (995)
Compound (B) (6.9 g, 5.9 mmol), 2,4-pentanedione (1.2 g, 11.7 mmol) and sodium carbonate (3.1 g, 29.4 mmol) were dissolved in 2-ethoxyethanol (100 mL), and the solution was heated for 4 hours. When the reaction was completed, the reaction mixture was cooled to room temperature, and the solid precipitate produced was filtered. Purification via silica gel column chromatography and recrystallization gave Compound (995) (4.2 g, 36%) as red crystal.
According to the same procedure as Preparation Example 1, organic electroluminescent compounds (Compound 1 through Compound 1009) in Table 1 were prepared, of which the 1H NMR and MS/FAB data are listed in Table 2.
1H NMR (CDCl3, 200 MHz)
An OLED device was manufactured by using an organic electroluminescent compound according to the invention.
First, a transparent electrode ITO thin film (15Ω/□) (2) prepared from glass for OLED (produced by Samsung Corning) (1) 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) 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 injection 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(a-naphthyl)-N,N′-diphenyl-4,4′-diamine (NPB), and electric current was applied to the cell to evaporate NPB, thereby providing vapor-deposit of a hole transport layer (4) of 20 nm of thickness on the hole injection layer.
To another cell of said vacuum vapor-deposit device, charged was 4,4′-N,N′-dicarbazole-biphenyl (CBP) as an electroluminescent host material, and an organic electroluminescent compound (e.g. Compound 1) according to the present invention was charged to still another cell. The two materials were evaporated at different rates to carry out doping to vapor-deposit an electroluminescent layer (5) having 30 nm of thickness on the hole transport layer. The suitable doping concentration is 4 to 10 mol % on the basis of CBP.
Then, on the electroluminescent layer, bis(2-methyl-8-quinolinato)(p-phenylphenolato)aluminum (III) (BAlq) was vapor-deposited as a hole blocking layer in a thickness of 10 nm in the same manner for NPB, tris(8-hydroxyquinoline)aluminum (III) (Alq) was vapor-deposited as an electron transport layer (6) in a thickness of 20 nm, and then lithium quinolate (Liq) was vapor-deposited as an electron injection layer (7) in a thickness of 1 to 2 nm. Thereafter, an Al cathode (8) was vapor-deposited in a thickness of 150 nm by using another vacuum vapor-deposit device to manufacture an OLED.
A hole injection layer and a hole transport layer were formed according to the procedure of Example 1, and an electroluminescent layer was vapor-deposited thereon as follows. To another cell of said vacuum vapor-deposit device, charged was H-2 as an electroluminescent host material according to the invention, and an organic electroluminescent compound (Compound 177) according to the present invention was charged to still another cell. The two materials were evaporated at different rates to carry out doping to vapor-deposit an electroluminescent layer (5) having 30 nm of thickness on the hole transport layer. The suitable doping concentration is 4 to 10 mol % on the basis of the host. Then, a hole blocking layer, an electron transport layer and an electron injection layer were vapor-deposited according to the same procedure as in Example 1, and then Al cathode was vapor-deposited in a thickness of 150 nm by using another vacuum vapor-deposit device to manufacture an OLED.
A hole injection layer, a hole transport layer and an electroluminescent layer were formed according to the same procedure as in Example 2, and then an electron transport layer and an electron injection layer were vapor-deposited. Thereafter, Al cathode was vapor-deposited in a thickness of 150 nm by using another vacuum vapor-deposit device to manufacture an OLED.
In order to confirm the performance of the OLED's prepared according to Example 1, the luminous efficiency of the OLED's was measured at 10 mA/cm2. Various properties are shown in Tables 3.
For Compound (10), incorporation of 2-naphthyl affected the HOMO level, and provided the effect of enhanced color coordinate, even though the efficiency was somewhat lowered. Compounds (177), (374) and (589), wherein 2-phenylquinonline, ppy, phenyl(6-phenylpyridin-3-yl)methanone were incorporated as a subsidiary ligand, respectively, showed the highest luminous efficiencies (11.6 cd/A, 11.4 cd/A and 12.1 cd/A, respectively) among the compounds according to the present invention. Thus, the luminous efficiency of a phosphorescent device can be enhanced by using an appropriate subsidiary ligand.
With identical device structure, using the host according to the present invention instead of CBP in an EL device did not provide significant change in efficiency, color coordinate and operation voltage from those of CBP. Thus it is anticipated that those hosts can be employed as a phosphorescent host, when being used with dopants according to the invention, instead of CBP as a conventional electroluminescent host. When the host according to the invention is employed without using a hole blocking layer, the device exhibits comparable or higher luminous efficiency as compared to that using conventional hosts, and provides decreased power consumption of the OLED due to lowered operation voltage by 0.8˜0.9 V. If the invention is applied to mass production of OLED's, the time for mass production can be also shortened to give great benefit on the commercialization.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2007-0116792 | Nov 2007 | KR | national |
