WO2009005272A2

WO2009005272A2 - Organometallic complex compounds for organic light emitting display device and organic light emitting display device including the same

Info

Publication number: WO2009005272A2
Application number: PCT/KR2008/003826
Authority: WO
Inventors: Hyung-Sun Kim; Ho-Jae Lee; Eun-Sun Yu; Nam-Soo Kim; Young-Hoon Kim; Mi-Young Chae
Original assignee: Cheil Industries Inc
Current assignee: Cheil Industries Inc
Priority date: 2007-06-29
Filing date: 2008-06-30
Publication date: 2009-01-08
Anticipated expiration: 2009-12-29
Also published as: TW200923047A; TWI487770B; KR20090001072A; KR100907564B1; WO2009005272A3

Abstract

A metallic complex compound for an organic light emitting display device includes an asymmetric fluorene derivative ligand. The metallic complex compound for an organic light emitting display device has improved solubility due to bulky substituents, and thereby forms a thin layer using a wet process such as spin coating, InkJet printing, or casting during manufacture of a device. Additionally, the metallic complex compound can reduce manufacturing cost of an organic light emitting display device, and improve luminous efficiency since the bulky substituents inhibits molecular mutual interaction.

Description

ORGANOMETALLIC COMPLEX COMPOUNDS FOR

ORGANIC LIGHT EMITTING DISPLAY DEVICE AND

ORGANIC LIGHT EMITTING DISPLAY DEVICE INCLUDING

THE SAME Technical Field

[1] The present invention relates to a metallic complex compound for an organic light emitting display device, and an organic light emitting display device including the same for a light emitting dopant. More particularly, the present invention relates to a metallic complex compound that is an emission-layer-forming material for an organic light emitting display device, and an organic light emitting display device including the same for a light emitting dopant.

[2]

Background Art

[3] An organic light emitting display device is a self light emitting display device that can be driven at a low voltage, and has a wide viewing angle, good contrast, and fast response speed. It can also be lightweight and thin since it does not need a backlight.

[4] In 1987, Eastman Kodak, Inc., firstly developed an organic light emitting display device including a low molecular aromatic diamine and aluminum complex as an emission-layer-forming material [Appl. Phys. Lett. 51, 913, 1987]. C. W. Tang et al. firstly disclosed a practicable device as an organic light emitting display device in 1987 (Applied Physics Letters, 51, 12, 913-915, 1987). According to the references, the organic layer has a structure in which a thin film (hole transport layer (HTL)) of a diamine derivative and a thin film of tris(8-hydroxy-quinolate)aluminum (AIq₃) are laminated.

[5] Generally, an light emitting display device is composed of an anode of a transparent electrode, an organic thin layer of a light emitting region, and a metal electrode (cathode) formed on a glass substrate, in that order.

[6] The organic thin layer may include an emission layer, a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and an electron injection layer (EIL). It may further include an electron inhibition layer or a hole inhibition layer due to the emission characteristics of the emission layer.

[7] The light emitting display device is applied with an electric field, and the holes and electrons are injected from the anode and the cathode, respectively. The injected holes and electrons are recombined on the emission layer though the hole transport layer (HTL) and the electron transport layer (ETL) to provide light emitting excitons. The provided light emitting excitons emit light by transiting to the ground state. Herein, a light emitting colorant (dopant) is doped to an emission layer (host) to increase light emitting efficiency and stability.

[8] In the light emitting display device, light emitting materials may be classified as a fluorescent material including singlet excitons and a phosphorescent material including triplet excitons according to the light emitting mechanism.

[9] Recently, it is has become known that a phosphorescent light emitting material can be used for a light emitting material in addition to the fluorescent light emitting material (D. F. O'Brien et al., Applied Physics Letters, 74 3, 442-444, 1999; M. A. Baldo et al., Applied Physics letters, 75 1, 4-6, 1999).

[10] Such a phosphorescent material emits light by transiting electrons from a ground state to an exited state, non-radiance transiting of a singlet exciton to a triplet exciton through intersystem crossing, and transiting a triplet exciton to a ground state to emit light.

[11] When the triplet exciton is transited, it cannot directly transit to the ground state.

Therefore, the electron spin is flipped and then it is transited to the ground state, so that it provides a characteristic of extending the lifetime (emission duration) to more than that of fluorescent emission.

[12] In other words, the duration of fluorescent emission is extremely short at several nanoseconds, but the duration of phosphorescent emission is relatively long such as at several microseconds.

[13] In addition, evaluating quantum mechanically, when holes injected from the anode are recombined with electrons injected from the cathode to provide light emitting excitons, the singlet and the triplet are produced in a ratio of 1:3, in which the triplet light emitting excitons are produced at three times the amount of the singlet light emitting excitons in the light emitting display device.

[14] Accordingly, the percentage of the singlet exited state is 25% (the triplet is 75%) in the case of a fluorescent material, so it has limits in luminous efficiency. On the other hand, in the case of a phosphorescent material, it can utilize 75% of the triplet exited state and 25% of the singlet exited state, so theoretically the internal quantum efficiency can reach up to 100%. When a phosphorescent light emitting material is used, it has advantages in an increase in luminous efficiency of around four times that of the fluorescent light emitting material.

[15] A phosphorescent light emitting material has a molecule structure appropriate for intersystem crossing. The molecule structure includes heavy metals such as Ir, Pt, Rh, or Pd in an organic molecule, which incurs spin-orbital coupling and thus triplets and singlets are mixed. Thereby, inhibited transition is allowed and phosphorescent light emission at room temperature can effectively occur.

[16] An iridium organic metallic complex has garnered interest due to excellent phosphorescent luminous efficiency, and phosphorescent light emitting materials including such a metallic complex have been reported [Sergey Lamansky et al. Inorg. Chem., 40, 1704-1711, 2001 & J. Am. Chem. Soc, 123, 4304-4312, 2001].

[17]

Disclosure of Invention Technical Problem

[18] Such an organic metallic complex for phosphorescent light emission is a low molecular material that is applicable using a general dry process such as vacuum deposition. In the case of a polymer material, it can be applied to a device using a wet process such as spin coating, InkJet printing, or casting.

[19] The wet process using a polymer allows ease of device manufacture compared with a dry process such as vacuum deposition, and has merits in terms of costs and scalability. However, polymer materials have problems of lower life-span, luminous efficiency, color purity, and so on compared with low molecular materials.

[20] Therefore, in order to solve the problems, development of a low material that is applicable to a wet process due to high solubility has been required.

[21]

Technical Solution

[22] According to one embodiment of the present invention, provided is a metallic complex compound for an organic light emitting display device that has improved solubility due to bulky substituents, and is therefore applied using a wet process such as spin coating, InkJet printing, or casting during manufacture of a device. According to another embodiment, provided is an organic light emitting display device including the metallic complex compound.

[23] The metallic complex compound for an organic light emitting display device includes a symmetric fluorene derivative ligand represented by the following Formula 1:

[24] [Chemical Formula 1]

[25]

[26] wherein n is an integer ranging from 1 to 3, and a and b are independently 0 or 1;

[27] the above cycle of Formula 1 may be a cycle including a double bond or a single bond;

[28] M is a metal to form an octahedral complex;

[29] L is a didentate ligand of a monovalent anion bound to M through a coordinate covalent bond with an sp² carbon and a heteroatom, or a didentate ligand of a monovalent anion bound to M through a coordinate covalent bond with a heteroatom and an unshared electron pair of a heteroatom;

[30] Y¹ is a monodentate ligand bound to M through a coordinate covalent bond with an unshared electron pair of heteroatom, and Y² is a monodentate ligand bound to M through a coordinate covalent bond with an sp² carbon and nitrogen atom of a monovalent anion; and

[31] X¹ to X⁸ are carbon atoms or heteroatoms, and when one of X¹ to X⁸ is a carbon atom, R¹ to R⁸ bound to X¹ to X⁸ are substituents bound to the carbon atom, or

[32] when one of X¹ to X⁸ is nitrogen, oxygen, or sulfur, R¹ to R⁸ bound to X¹ to X⁸ are unshared electron pairs, or R¹ to R⁸ form a fused ring bound to X¹ to X⁸.

[33] R¹ to R⁸ are independently selected from the group consisting of hydrogen, a substituted or unsubstituted aryl having a carbon number of 6 or more, a substituted or un- substituted heteroaryl having a carbon number of 2 or more, a substituted or unsubstituted alkyl having a carbon number of 1 or more, a substituted or unsubstituted amino having a carbon number of 2 or more, a substituted or unsubstituted alkoxy having a carbon number of 1 or more, a halogen, a nitro, a substituted or unsubstituted arylene having a carbon number of 6 or more, a substituted or unsubstituted het- eroarylene having a carbon number of 2 or more, and a substituted or unsubstituted alkylene having a carbon number of 1 or more.

[34] The compound of the above Formula 1 is an aromatic cyclic compound.

[35] The metal (M) to form an octahedral complex is iridium.

[36] The substituents of R¹ to R⁸ may have a fluorene structure selected from the group consisting of the following Formulae 2 and 3:

[37] [Chemical Formula 2]

[39] [Chemical Formula 3]

[41] wherein R⁹ is independently one selected from the group consisting of hydrogen, a halogen, R", OR⁴, N(R¹¹K P(R¹¹K P(OR¹¹K POR¹¹, PO₂R¹¹, PO₃R¹¹, SR¹¹, Si(R¹¹K Si(CHs)₂R¹¹, Si(Ph)₂R¹¹, B(R¹¹K B(OR¹¹K C(O)R¹¹, C(O)OR¹¹, C(O)N(R¹¹K CN, NO₂, SO₂, SOR¹¹, SO₂R¹¹, and SO₃R¹¹;

[42] R¹¹ is selected from the group consisting of hydrogen, a linear or branched Cl to C30 alkyl, a linear or branched C2 to C30 alkenyl, a linear or branched C2 to C30 alkynyl, a linear or branched Cl to C30 heteroalkyl, a C6 to C40 aryl, and a C3 to C40 heteroaryl, wherein R¹¹ is substituted with at least one substituent, Z;

[43] Z is selected from the group consisting of R¹², OR¹², N(R¹²K P(R¹²K P(OR¹²K POR i2, PO₂R¹², PO₃R¹², SR¹², Si(R¹²K Si(CH₃)₂R¹², Si(Ph)₂R¹², B(R¹²K B(OR¹²K C(O)R¹², C(O)OR¹², C(O)N(R¹²K CN, NO₂, SO₂, SOR¹², SO₂R¹², and SO₃R¹²;

[44] R¹² is selected from the group consisting of hydrogen, a linear or branched Cl to C30 alkyl, a linear or branched C2 to C30 alkenyl, a linear or branched C2 to C30 alkynyl, a linear or branched Cl to C30 heteroalkyl, a C6 to C40 aryl, and a C3 to C40 heteroaryl; and

[45] R¹⁰ is selected from the group consisting of a substituted or unsubstituted aryl having a carbon number of 6 or more, a substituted or unsubstituted heteroaryl having a carbon number of 2 or more, a substituted or unsubstituted alkyl having a carbon number of 1 or more, a substituted or unsubstituted amino having a carbon number of 2 or more, a substituted or unsubstituted alkoxy having a carbon number of 1 or more, a halogen, a nitro, a substituted or unsubstituted arylene having a carbon number of 6 or more, a substituted or unsubstituted heteroarylene having a carbon number of 2 or more, and a substituted or unsubstituted alkylene having a carbon number of 1 or more.

[46] According to one embodiment, L is a ligand selected from the group consisting of the following lignads (1) to (9):

CD (2) (3) (4) (5)

£6) (7) (8) (9⁾

[48] The metallic complex compound of the above Formula 1 for an organic light emitting display device according to one embodiment may be a compound selected from the group consisting of the following Formulae Ia to Ig, but is not limited thereto.

[49] [Chemical Formula Ia] [50]

[51] [Chemical Formula Ib]

[53] [Chemical Formula Ic]

[55] [Chemical Formula Id]

[56]

[57] [Chemical Formula Ie]

[59] [Chemical Formula If]

[61] [Chemical Formula Ig]

[63] In the above Formulae Ia to Ig, R and R' are independently a linear or branched Cl to C30 alkyl and M is a metal to form an octahedral complex. [64] The organic light emitting display device according to another embodiment includes a first electrode disposed on a substrate, an organic thin layer including the metallic complex compound disposed on the first electrode, and a second electrode disposed on the organic thin layer.

[65] The organic thin layer includes at least one of a first buffer layer for hole injection or transport, disposed on the first electrode layer, an emission layer disposed on the first buffer layer, and a second buffer layer for electron injection or transport, disposed on the emission layer.

[66] The first electrode is formed of a transparent conductive metal oxide selected from the group consisting of ITO (indium tin oxide), IZO (indium zinc oxide), tin oxide, zinc oxide, and combinations thereof.

[67] The substrate may be a glass substrate or a flexible substrate. [68] The emission layer may be formed using at least one of spin coating, InkJet printing, and casting.

Advantageous Effects

[69] The metallic complex compound for an organic light emitting display device inhibits molecular mutual interaction by introducing bulky substituents as a ligand, resulting in improvement of solubility.

[70] The metallic complex compound can be applicable to a wet process such as spin coating, InkJet printing, casting, and so on during manufacture of an organic light emitting display device, resulting in a manufacturing cost reduction of an organic light emitting display device. Brief Description of the Drawings [71] FIG. 1 is a view of an organic light emitting display device according to one embodiment of the present invention. Best Mode for Carrying Out the Invention

[72] In the present specification, when specific definition is not provided, "aryl or "arylene refers to a C6 to C40 aryl or arylene, "heteroaryl or "heteroarylene" refers to a C2 to C40 heteroaryl or heteroarylene, "alkyl," "alkylene" or "alkoxy" refers to a Cl to C30 alkyl, alkylene, or alkoxy, and "heteroalkyl" refers to a Cl to C30 heteroalkyl.

[73] In the present specification, when specific definition is not provided, the term "substituted" refers to one substituted with at least a substituent selected from the group consisting of an aryl, a heteroaryl, an alkyl, an amino, an alkoxy, a halogen (F, Cl, Br, or I), and a nitro.

[74] In the present specification, when specific definition is not provided, the term "hetero" refers to one including 1 to 10 heteroatoms selected from the group consisting of N, O, S, and Si.

[75] The metallic complex compound for an organic light emitting display device includes an asymmetric fluorene derivative ligand represented by the following Formula 1:

[76] [Chemical Formula 1]

[78] wherein n is an integer ranging from 1 to 3, and a and b are independently 0 or 1; [79] the above cycle of Formula 1 may be a cycle including a double bond or a single bond; [80] M is a metal to form an octahedral complex;

[81] L is a didentate ligand of a monovalent anion bound to M through a coordinate covalent bond with an sp² carbon and a heteroatom, or a didentate ligand of a monovalent anion bound to M through a coordinate covalent bond with a heteroatom and an unshared electron pair of a heteroatom;

[82] Y¹ is a monodentate ligand bound to M through a coordinate covalent bond with an unshared electron pair of a heteroatom, and Y² is a monodentate ligand bound to M through a coordinate covalent bond with an sp² carbon and nitrogen atom of a monovalent anion; and

[83] X¹ to X⁸ are a carbon atom or a heteroatom, and when one of X¹ to X⁸ is a carbon atom, R¹ to R⁸ bound to X¹ to X⁸ are substituents bound to the carbon atom, or

[84] when one X¹ to X⁸ is nitrogen, oxygen, or sulfur, R¹ to R⁸ bound to X¹ to X⁸ are unshared electron pairs, or R¹ to R⁸ form a fused ring bound to X¹ to X⁸.

[85] R¹ to R⁸ are independently selected from the group consisting of hydrogen, a substituted or unsubstituted aryl having a carbon number of 6 or more, a substituted or un- substituted heteroaryl having a carbon number of 2 or more, a substituted or unsubstituted alkyl having a carbon number of 1 or more, a substituted or unsubstituted amino having a carbon number of 2 or more, a substituted or unsubstituted alkoxy having a carbon number of 1 or more, a halogen, a nitro, a substituted or unsubstituted arylene having a carbon number of 6 or more, a substituted or unsubstituted het- eroarylene having a carbon number of 2 or more, and a substituted or unsubstituted alkylene having a carbon number of 1 or more.

[86] The metallic complex compound includes a five-member ring when a and b are 0, a six-member ring when a=b=l, and both a five-member ring and a six-member ring when a=0 and b=l, or a=l and b=0.

[87] The compound of the above Formula 1 is an aromatic cyclic compound.

[88] The metal (M) to form an octahedral complex is iridium.

[89] The substituent of R¹ to R⁸ may have a fluorene structure selected from the group consisting of the following Formulae 2 and 3:

[90] [Chemical Formula 2]

[92] [Chemical Formula 3]

[94] wherein R⁹ isindependently one selected from the group consisting of hydrogen, a halogen, R", OR⁴, N(R¹¹K P(R¹¹K P(OR¹¹K POR¹¹, PO₂R¹¹, PO₃R¹¹, SR¹¹, Si(R¹¹K Si(CHs)₂R¹¹, Si(Ph)₂R¹¹, B(R¹¹K B(OR¹¹K C(O)R¹¹, C(O)OR¹¹, C(O)N(R¹¹),, CN, NO₂, SO₂, SOR¹¹, SO₂R¹¹, and SO₃R¹¹;

[95] R¹¹ is selected from the group consisting of hydrogen, a linear or branched Cl to C30 alkyl, a linear or branched C2 to C30 alkenyl, a linear or branched C2 to C30 alkynyl, a linear or branched Cl to C30 heteroalkyl, a C6 to C40 aryl, and a C6 to C40 heteroaryl, wherein R¹¹ is substituted with at least one substituent, Z;

[96] Z is selected from the group consisting of R¹², OR¹², N(R¹²)₂, P(R¹²)₂, P(OR¹²)₂, POR i2, PO₂R¹², PO₃R¹², SR¹², Si(R¹²)₃, Si(CH₃)₂R¹², Si(Ph)₂R¹², B(R¹²)₂, B(OR¹²K C(O)R¹², C(O)OR¹², C(O)N(R¹²K CN, NO₂, SO₂, SOR¹², SO₂R¹², and SO₃R¹²;

[97] R¹² is selected from the group consisting of hydrogen, a linear or branched Cl to C30 alkyl, a linear or branched C2 to C30 alkenyl, a linear or branched C2 to C30 alkynyl, a linear or branched Cl to C30 heteroalkyl, a C6 to C40 aryl, and a C3 to C40 heteroaryl; and

[98] R¹⁰ is selected from the group consisting of a substituted or unsubstituted aryl having a carbon number of 6 or more, a substituted or unsubstituted heteroaryl having a carbon number of 2 or more, a substituted or unsubstituted alkyl having a carbon number of 1 or more, a substituted or unsubstituted amino having a carbon number of 2 or more, a substituted or unsubstituted alkoxy having a carbon number of 1 or more, a halogen, a nitro, a substituted or unsubstituted arylene having a carbon number of 6 or more, a substituted or unsubstituted heteroarylene having a carbon number of 2 or more, and a substituted or unsubstituted alkylene having a carbon number of 1 or more.

[99] According to one embodiment, L is a ligand selected from the group consisting of the following lignads (1) to (9):

[100]

CD (2) (3) (4) (5)

£6) (7) (8) (9)

[101] The metallic complex compound of the above Formula 1 for an organic light emitting display device according to one embodiment may be a compound selected from the group consisting of the following Formulae Ia to Ig, but is not limited thereto.

[ 102] [Chemical Formula 1 a]

[103]

[104] [Chemical Formula Ib] [105]

[106] [Chemical Formula Ic]

[108] [Chemical Formula Id]

[110] [Chemical Formula 1 e]

[112] [Chemical Formula 1 f]

[114] [Chemical Formula Ig]

[116] In the above Formulae Ia to Ig, R and R' are a linear or branched Cl to C30 alkyl and M is a metal to form an octahedral complex. [117] The above metallic complex compound can be applied as a light emitting dopant of an organic light emitting display device.

[118] FIG. 1 is a view of organic light emitting display device according to one embodiment of the present invention.

[119] The organic light emitting display device 1 according to one embodiment includes a first electrode (anode, 20) disposed on a substrate 10, an organic thin layer 100 including the metallic complex compound disposed on the first electrode, and a second electrode (cathode, 30) disposed on the organic thin layer 100.

[120] The organic thin layer 100 includes at least one of a first buffer layer 110 for hole injection or transport, disposed on the first electrode 20, an emission layer 120 disposed on the first buffer layer 110, and a second buffer layer 130 for electron injection or transport, disposed on the emission layer 120. At least one layer of the organic thin layer 100 includes the metallic complex compound according to one embodiment of the present invention.

[121] The first buffer layer 110 may include at least one selected from the group consisting of a hole injection layer (HIL) and a hole transport layer (HTL), and may further include an electron inhibition layer to improve light emitting characteristics of the emission layer 120.

[122] The second buffer layer 130 may include at least one selected from the group consisting of an electron injection layer (EIL) and an electron transport layer (ETL), and may further include a hole inhibition layer to improve light emitting characteristics of the emission layer 120.

[123] A third buffer layer (not shown) may be disposed between the first electrode 20 and the first buffer layer 120 to complement an anode surface and help hole injection and flow.

[124] The third buffer layer may include a polymer such as doped poly aniline (PANI) or doped polyethylene dioxythiophene (PEDOT), or a low molecular material such as alpha-CuPc.

[125] The first electrode 20 is formed of a transparent conductive metal oxide selected from the group consisting of ITO (indium tin oxide), IZO (indium zinc oxide), tin oxide, zinc oxide, and combinations thereof.

[126] The substrate 10 may be a glass substrate or a flexible substrate.

[127] The emission layer 120 is formed of a host and a dopant using a wet process such as spin coating, InkJet printing, or casting. The host may be TMM038 (Merck, low molecule), PVK (polyvinyl carbazole), or PVK/CBP (4,4'-N,N'-dicarbazolebiphenyl) (45:55 or 1:1 weight ratio), and the dopant is the metallic complex compound according to one embodiment of the present invention. The metallic complex compound may be included in an amount of 1 to 30 wt% based on the total weight of emission layer materials. In one embodiment, the metallic complex compound may be included in an amount of 3 to 10 wt% based on the total weight of emission layer materials. Within the above range, preferable device characteristics can be obtained.

[128] When the organic light emitting display device 1 is applied with an electric field, the holes and electrons are injected from the first electrode 20 and the second electrode 30, respectively. The injected holes and electrons are recombined on the emission layer though the hole transport layer (HTL) and the electron transport layer (ETL) to provide light emitting excitons.

[129] The provided light emitting excitons emit light by transiting to the ground state. [130] The following examples illustrate the present invention in more detail. However, it is understood that the present invention is not limited by these examples.

[131] Example 1: Synthesis of Chemical Formula 1 a'

Ligand a

[rύcac)-. gycerol

[133] 14.0 g (1.1 eq, 61.1 mmol) of 1,3-dibromobenzene was dissolved in 200ml of tet- rahydrofuran. A reaction temperature was cooled to -78°C, and then 39.8ml (1.15eq, 63.8 mmol) of n-butyl lithium (1.6M in n-hexane) was slowly added in a drop wise fashion.

[134] After agitating for 30 minutes, 10.0 g (l.Oeq, 55.5 mmol) of fluorenone dissolved in 100ml of tetrahydrofuran was slowly added in a drop wise fashion. The resulting mixture was agitated for 12 hours under nitrogen gases while raising the reaction temperature to room temperature.

[135] When reaction was complete, extraction with diethylether was performed. An resulting organic layer was dried using anhydrous magnesium sulfate, concentrated, and then separated using silica gel column chromatography to obtain 9-(3-bromophenyl)-9H-fluorene-9-ol.

[136] 5.0 g (l.Oeq, 14.8 mmol) of 9-(3-bromophenyl)-9H-fluorene-9-ol and 2.5g (l.leq, 21.0mmol) of 4-isobutyl benzene were dissolved in dichloromethane. Then, meth- anesulfonic acid diluted with dichloromethane was added to the solution in a catalytic amount in a dropwise fashion. The resulting product was agitated at room temperature for 12 hours.

[137] When reaction was complete, an organic layer was extracted with dichloromethane, dried for concentration with anhydrous magnesium sulfate, and then separated using silica gel column chromatography, to obtain 2-(3-(9-(4-isobutylphenyl)-9H-fluorene-9-yl)phenyl) bromide.

[138] 4.Og (l.Oeq, 8.8 mmol) of 3-(9-(4-isobutylphenyl)-9H-fluorene-9-yl)phenyl bromide was dissolved in 50 ml of THF. The solution was cooled to -78⁰C, and 9.73 ml (1.2 eq, 11 mmol) of n-butyl lithium (1.6M in hexane) was slowly added thereto in a dropwise fashion.

[139] The resulting product was agitated for 30 minutes, and 1.96g (1.3 eq, 11.5mmol) of 2-isopropoxy-4,4,5,5-tetramethyl-l,3,2-dioxaborolane was slowly added thereto in a dropwise fashion. Then, the resulting product was increased to room temperature and agitated for 12 hours.

[140] When reaction was complete, extraction with diethylether was performed. The organic layer was dried, concentrated, and then separated using silica gel column chromatography, to obtain an intermediate 3.

[141] Next, ligand a was synthesized using a Suzuki coupling reaction. 2g (leq, 4 mmol) of the intermediate 3 and 0.59g (0.9 eq, 3.6 mmol) of 1-chloroisoquinoline were dissolved in 10ml of a 2M potassium carbonate aqueous solution and 20ml of THF. Then, O.lg (2 mol%) tetrakis(triphenylphosphine)palladiumwith an oxidation number of 0 was added thereto under a nitrogen flow and refluxed for 12 hours.

[142] When the reaction was complete, tetrakis(triphenylphosphine) palladium was removed by performing celite filtration. Then, an organic layer was extracted with diethylether. The organic layer was dried, concentrated, and then separated with silica gel column chromatography, to obtain ligand a.

[143] 0.46 g (4.5 eq, 0.9 mmol) of the ligand a and O.lg (0.2 mmol) of iridium acet- ylacetonate were added to glycerol and heated under a nitrogen flow at 200⁰C for 24 hours, and then agitated.

[144] When the reaction was complete, the reactant was put into distilled water. Then, a solid was filtered therefrom, dissolved in chloroform, and separated using silica gel column chromatography, obtaining compound Ia' including an asymmetric fluorene derivative ligand, as a bulky ligand.

[145] Example 2: Synthesis of Chemical Formula 1 b' [146] The intermediate 3 in Example 1 was reacted with l-(4'-bromophenyl)isoquinoline to synthesize the corresponding ligand b using a Suzuki coupling reaction. The compound of the following formula Ib' was obtained using the ligand according to the same method as in Example 1.

[147] [Chemical Formula Ib']

[149] Example 3: Synthesis of Chemical Formula 1 c' [150] The intermediate 3 in Example 1 was reacted with l-(3'-bromophenyl)isoquinoline to synthesize the corresponding ligand c using a Suzuki coupling reaction. The compound of the following formula Ic' was obtained using the ligand according to the same method as in Example 1.

[151] [Chemical Formula Ic'] [152]

[153] Example 4: Synthesis of Chemical Formula 1 d' [154] The intermediate 4 having the following formula was reacted with l-(4'-bromophenyl)isoquinoline to synthesize the corresponding ligand d using a Suzuki coupling reaction. The compound of the following formula Id' was obtained using the ligand according to the same method as in Example 1.

[155] [Intermediate 4]

[157] [Chemical Formula Id'] [158]

[159] Example 5: Synthesis of Chemical Formula 1 e' [160] The intermediate 3 in Example 1 was reacted with 4-bromophenylpyridine to synthesize the corresponding ligand e using a Suzuki coupling reaction. The compound of the following formula Ie' was obtained using the ligand according to the same method as in Example 1.

[161] [Chemical Formula Ie']

[163] Example 6: Synthesis of Chemical Formula 1 f ' [164]

Ligand f

jyoeroi

[f

[165] Ligand f was prepared according to a similar process to Example 1. 0.3 g (2 eq, 0.66 mmol) of the ligand f and 0.2g (0.33 mmol) of Ir(ppy)₂(acac) were dissolved in glycerol. The resulting product was heated to 200 ⁰C for 24 hours under a nitrogen flow, and then agitated.

[166] When the reaction was complete, the reactant was put into distilled water. Then, a solid was filtered therefrom, dissolved in chloroform, and then separated by silica gel column chromatography, obtaining a compound If including an asymmetric fluorene derivative ligand as a bulky ligand.

[167] Example 7: Synthesis of Chemical Formula Ig' [168]

glycerol

[169] Ligand g was prepared according to a similar process to Example 1. 0.65g (2 eq, 0.66 mmol) of the ligand g and 0.2g (0.33 mmol) of Ir(ppy)₂(acac) were dissolved in glycerol. The resulting product was heated to 200 ⁰C for 24 hours under a nitrogen flow, and then agitated.

[170] When the reaction was complete, the reactant was put into distilled water. Then, a solid was filtered therefrom, dissolved in chloroform, and then separated by silica gel column chromatography, obtaining compound Ig' including an asymmetric fluorene derivative ligand as a bulky ligand.

[171] Example 8: Fabrication of OLED device

[172] The metallic complex compounds Ia' to Id' prepared according to Examples 1-4 was used to prepare an electroluminescence display device of FIG. 1.

[173] First, a first electrode 20 was fabricated to have a size of 20mm x 20mm x 0.7mm on a 15Ω/cm² 1200A substrate 10 (Corning Inc.).

[174] The first electrode 20 included ITO (indium tin oxide) as a transparent conductive metal oxide. [175] The substrate 10 including the first electrode 20 was ultrasonic wave cleaned in isopropyl alcohol and pure water for 5 minutes, and then UV ozone cleaned for 30 minutes. [176] Then, the first electrode 20 was coated on the top thereof to form an organic thin layer 100 by spin-coating PEDOT (poly (e thy lenedioxy)thiophene). Next, an emission layer was spin-coated to be 500A thick on the PEDOT (poly(ethylenedioxy)thiophene) by using TMM038 (Merck, low molecular) as a host and the metallic complex compounds Ia' to Id' according to Examples 1 to 4 as a dopant (7wt% based on the total amount of the host and dopant).

[177] Next, BAIq was vacuum-deposited to form a 50A-thick hole inhibition layer on the emission layer 120. Subsequently, Alq3 was vacuum-deposited to form a 200A-thick electron transport layer (ETL) on the hole inhibition layer.

[178] Then, LiF at 1OA for an electron injection layer (EIL) and Al at 1000 A (cathode) were sequentially vacuum-deposited on the electron transport layer (ETL) to form the second electrode 30 with a LiF/Al metal, fabricating an organic light emitting display device 1.

[179] Example 9: Fabrication of OLED device

[180] An organic light emitting display device 1 shown in FIG. 1 was fabricated according to the same method as in Example 8, except that an emission layer was spin-coated to be 500 A thick on the PEDOT (poly(ethylenedioxy)thiophene) by using PVK/CBP (4,4'-N,N'-dicarbazolebiphenyl) (1:1 weight ratio) as a host and the metallic complex compounds Ie' to Ig' according to Examples 5 to 7 as a dopant (7wt% based on the total amount of the host and dopant).

[181] The organic light emitting display devices 1 according to Examples 8 and 9 were evaluated by measuring initial driving voltage (turn-on voltage), driving voltage (V) at each of maximum luminance (cd/m²) and luminance of 1000 cd/m², current efficiency (cd/A), and electric power efficiency (ImAV). The results of Example 8 are shown in Table 1.

[182] Table 1 [Table 1] [Table ]

[183] As aforementioned, the metallic complex compound according to one embodiment of the present invention included in the organic thin layer 100 was fabricated into an organic light emitting display device 1 not by vacuum deposition but by spin coating, which is a wet process. However, the organic light emitting display device could emit pure red light with a color coordinate of x,y=[0.67, 0.33].

[184] In addition, its initial driving voltage was measured to be 2.8 - 5.0 V, and its maximum luminance ranged from 3847 cd/m² to 12,700 cd/m². As a result, it could have improved electrical stability.

[185] In addition, the device can be easily fabricated in a wet process by using the metallic complex compound with excellent solubility due to decreased van der Waals' force among molecules in an organic solvent such as toluene, chloroform, chlorobenzene, and the like, unlike Ir(piq)₃ or Ir(piq)₂(acac) that are known to have excellent effects among metallic complex compounds emitting red phosphorescent light.

[186] In other words, when a bulky substituent is introduced into a metallic complex compound of the present invention, the metallic complex compound can improve solubility since molecules therein become apart from one another, decreasing crys- tallinity. The molecules have suppressed interaction, resulting in improving luminous efficiency and electrical characteristics.

[187] Therefore, the metallic complex compound of the present invention can be usefully applied as a phosphorescent light emitting material of an organic light emitting display device.

[188] While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

[1] A metallic complex compound for an organic light emitting display device, comprising an asymmetric fluorene derivative ligand represented by the following Formula 1 : [Chemical Formula 1]

wherein n is an integer ranging from 1 to 3, and a and b are independently 0 or 1; the above cycle of Formula 1 may be a cycle including a double bond or a single bond;

M is a metal to form an octahedral complex;

L is a didentate ligand of a monovalent anion bound to M through a coordinate covalent bond with an sp² carbon and a heteroatom, or a didentate ligand of a monovalent anion bound to M through a coordinate covalent bond with a heteroatom and an unshared electron pair of a heteroatom;

Y¹ is a monodentate ligand bound to M through a coordinate covalent bond with an unshared electron pair of a heteroatom, and Y² is a monodentate ligand bound to M through a coordinate covalent bond with sp² carbon and nitrogen atom of a monovalent anion;

X¹ to X⁸ are a carbon atom or a heteroatom, and when one of X¹ to X⁸ is a carbon atom, R¹ to R⁸ bound to X¹ to X⁸ are substituents bound to the carbon atom, or when one X¹ to X⁸ is nitrogen, oxygen, or sulfur, R¹ to R⁸ bound to X¹ to X⁸ are unshared electron pairs, or R¹ to R⁸ form a fused ring bound to X¹ to X⁸; and R¹ to R⁸ are independently selected from the group consisting of hydrogen, a substituted or unsubstituted aryl having a carbon number of 6 or more, a substituted or unsubstituted heteroaryl having a carbon number of 2 or more, a substituted or unsubstituted alkyl having a carbon number of 1 or more, a substituted or unsubstituted amino having a carbon number of 2 or more, a substituted or unsubstituted alkoxy having a carbon number of 1 or more, a halogen, a nitro, a substituted or unsubstituted arylene having a carbon number of 6 or more, a substituted or unsubstituted heteroarylene having a carbon number of 2 or more, and a substituted or unsubstituted alkylene having a carbon number of 1 or more. [2] The metallic complex compound of claim 1, wherein the substituent of R¹ to R⁸ has a fluorene structure selected from the group consisting of the following Formulae 2 and 3:

[Chemical Formula 2]

[Chemical Formula 3]

wherein R⁹ isindependently one selected from the group consisting of hydrogen, a halogen, R", OR⁴, N(R¹¹K P(R¹¹K P(OR¹¹K POR¹¹, PO₂R¹¹, PO₃R¹¹, SR¹¹, Si(R¹¹K Si(CHs)₂R¹¹, Si(Ph)₂R¹¹, B(R¹¹K B(OR¹¹K C(O)R¹¹, C(O)OR¹¹, C(O)N(R¹¹K CN, NO₂, SO₂, SOR¹¹, SO₂R¹¹, and SO₃R¹¹;

R¹¹ is selected from the group consisting of hydrogen, a linear or branched Cl to C30 alkyl, a linear or branched C2 to C30 alkenyl, a linear or branched C2 to C30 alkynyl, a linear or branched Cl to C30 heteroalkyl, a C6 to C40 aryl, and a C6 to C40 heteroaryl, wherein R¹¹ is substituted with at least one substituent, Z; Z is selected from the group consisting of R¹², OR¹², N(R¹²K P(R¹²K P(OR¹²K POR¹², PO₂R¹², PO₃R¹², SR¹², Si(R¹²)₃, Si(CH₃)₂R¹², Si(Ph)₂R¹², B(R¹²)₂, B(OR¹²)₂, C(O)R¹², C(O)OR¹², C(O)N(R¹²)₂, CN, NO₂, SO₂, SOR¹², SO₂R¹², and SO₃R¹²; R¹² is selected from the group consisting of hydrogen, a linear or branched Cl to C30 alkyl, a linear or branched C2 to C30 alkenyl, a linear or branched C2 to C30 alkynyl, a linear or branched Cl to C30 heteroalkyl, a C6 to C40 aryl, and a C3 to C40 heteroaryl; and

R¹⁰ is selected from the group consisting of a substituted or unsubstituted aryl having a carbon number of 6 or more, a substituted or unsubstituted heteroaryl having a carbon number of 2 or more, a substituted or unsubstituted alkyl having a carbon number of 1 or more, a substituted or unsubstituted amino having a carbon number of 2 or more, a substituted or unsubstituted alkoxy having a carbon number of 1 or more, a halogen, a nitro, a substituted or unsubstituted arylene having a carbon number of 6 or more, a substituted or unsubstituted het- eroarylene having a carbon number of 2 or more, and a substituted or unsubstituted alkylene having a carbon number of 1 or more.

[3] The metallic complex compound of claim 1, wherein the compound of the above Formula 1 is an aromatic cyclic compound. [4] The metallic complex compound of claim 1, wherein L is a ligand selected from the group consisting of the following lignads (1) to (9):

(6) (7) (8) (9)

[5] The metallic complex compound of claim 1, wherein the metal (M) to form an octahedral complex is iridium.

[6] The metallic complex compound of claim 1, wherein the metallic complex compound of the above Formula 1 is a compound selected from the group consisting of the following Formulae Ia to Ig:

[Chemical Formula Ia]

[Chemical Formula Ib]

[Chemical Formula Ic]

M

[Chemical Formula Id]

[Chemical Formula Ie]

[Chemical Formula If]

[Chemical Formula Ig]

Wherein, in the above Formulae Ia to Ig, R and R' are independently a linear or branched Cl to C30 alkyl and M is a metal to form an octahedral complex.

[7] An organic light emitting display device comprising: a first electrode disposed on a substrate; an organic thin layer disposed on the first electrode; and a second electrode disposed on the organic thin layer, wherein the organic thin layer comprises the metallic complex compound according to one of claims 1 to 6.

[8] The organic light emitting display device of claim 7, wherein the organic thin layer comprises at least one of a first buffer layer for hole injection or transport, disposed on the first electrode layer, an emission layer disposed on the first buffer layer, and a second buffer layer for electron injection or transport, disposed on the emission layer.

[9] The organic light emitting display device of claim 7, wherein the first electrode is formed of a transparent conductive metal oxide selected from the group consisting of ITO (indium tin oxide), IZO (indium zinc oxide), and combinations thereof.

[10] The organic light emitting display device of claim 7, wherein the substrate is a glass substrate or a flexible substrate. [H] The organic light emitting display device of claim 7, wherein the emission layer is formed using at least one of spin coating, InkJet printing, and casting.