Materials for organic electroluminescent devices

Abstract

The present invention relates to dibenzofuran and dibenzothiophene derivatives, especially for use as triplet matrix materials in organic electroluminescent devices. The invention further relates to a process for preparing the compounds of the invention and to electronic devices comprising these.

Claims

1. A compound of formula (1d) ##STR00329## where the symbols used are as follows: Y.sup.1 is O, S, or NR, where the R radical bonded to N is not H or D; L.sup.1 is a single bond; L.sup.2 is a single bond; o is 0, 1, 2 or 3; p is 0, 1 or 2; N′ is a group of the formula (L-1) ##STR00330## where the dotted bond represents the linkage to L.sup.2; Y.sup.2 is the same or different at each instance and is selected from a single bond, C(R).sub.2, O, S, NR, where the R radical bonded to N is not H or D; n is the same or different at each instance and is 0 or 1, where, when at least one Y.sup.2 is a single bond, at least two n are 1; Ar is the same or different at each instance and is an aromatic ring system which has 6 to 18 aromatic ring atoms and may be substituted by one or more R.sup.3 radicals, or a dibenzofuranyl or dibenzothienyl group, each of which may be substituted by one or more R.sup.3 radicals; HetAr is a group of one of the formulae (2-1), to (4-1) ##STR00331## ##STR00332## where the dotted bond represents the linkage of this group; X is the same or different at each instance and is CR.sup.2 or N, with the proviso that at least one X symbol is N; R, R.sup.1, R.sup.2, R.sup.3 is the same or different at each instance and is selected from the group consisting of H, D, F, CN, N(Ar.sup.1).sub.2, N(R.sup.4).sub.2, a straight-chain alkyl or alkoxy group having 1 to 10 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 10 carbon atoms, each of which may be substituted by one or more R.sup.4 radicals, where one or more nonadjacent CH.sub.2 groups may be replaced by O, and where one or more hydrogen atoms may be replaced by D or F, an aromatic or heteroaromatic ring system which has 5 to 24 aromatic ring atoms and may be substituted in each case by one or more R.sup.4 radicals, and an aralkyl or heteroaralkyl group which has 5 to 25 aromatic ring atoms and may be substituted by one or more R.sup.4 radicals; at the same time, it is optionally possible for two adjacent R substituents, or two adjacent R.sup.1 substituents, or two adjacent R.sup.2 substituents, or two adjacent R.sup.3 substituents to form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system which may be substituted by one or more R.sup.4 radicals; where R.sup.1, if Y.sup.1 is O or S and if connected to the 9-position of the resultant dibenzofuran or dibenzothiophene, or if Y.sup.1 is NR and if connected to the 5-position of the resultant carbazole, is H; Ar.sup.1 is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 30 aromatic ring atoms and may be substituted by one or more nonaromatic R.sup.4 radicals; at the same time, two Ar.sup.1 radicals bonded to the same nitrogen atom, phosphorus atom or boron atom may also be bridged to one another by a single bond or a bridge selected from N(R.sup.4), C(R.sup.4).sub.2, O and S; R.sup.4 is the same or different at each instance and is selected from the group consisting of H, D, F, CN, N(R.sup.5).sub.2, a straight-chain alkyl, or alkoxy group having 1 to 10 carbon atoms or a branched or cyclic alkyl, or alkoxy group having 3 to 10 carbon atoms, each of which may be substituted by one or more R.sup.5 radicals, where one or more nonadjacent CH.sub.2 groups may be replaced O, and where one or more hydrogen atoms may be replaced by D or F, an aromatic or heteroaromatic ring system which has 5 to 24 aromatic ring atoms and may be substituted in each case by one or more R.sup.5 radicals, at the same time, it is optionally possible for two adjacent R.sup.4 substituents to form an aliphatic or aromatic or heteroaromatic ring system which may be substituted by one or more R.sup.5 radicals; R.sup.5 is the same or different at each instance and is selected from the group consisting of H, D, F, CN, an aliphatic hydrocarbyl radical having 1 to 10 carbon atoms, and an aromatic or heteroaromatic ring system having 5 to 13 aromatic ring atoms in which one or more hydrogen atoms may be replaced by D or F, and which may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms; at the same time, it is possible for two or more adjacent R.sup.5 substituents together to form an aliphatic ring system; excluding the following compounds: ##STR00333##

2. The compound according to claim 1, wherein the N′ group is a group of the formulae (L-2) to (L-7) ##STR00334## where the symbols that occur have the definitions given in claim 1 and in addition: Y.sup.3 is the same or different at each instance and is selected from C(R).sub.2, O, S, NR, where the R radical bonded to N is not H or D.

3. The compound according to claim 2, wherein the N′ group is a group of the formula (L-7).

4. The compound according to claim 2, wherein Y.sup.3 is the same or different at each instance and is selected from O, S, NR, where the R radical bonded to N is not H or D.

5. The compound according to claim 1, wherein Y.sup.1 is O or S.

6. A formulation comprising at least one compound according to claim 1 and at least one solvent.

7. An electronic device comprising at least one compound according to claim 1.

8. An organic electroluminescent device, wherein the compound according to claim 1 is used as matrix material for fluorescent or phosphorescent emitters and/or in an electron transport layer and/or in an electron-blocking or exciton-blocking layer and/or in a hole transport layer.

Description

EXAMPLES

Synthesis Examples

(1) The syntheses which follow, unless stated otherwise, are conducted under a protective gas atmosphere in dried solvents. The compounds of the invention can be prepared by means of synthesis methods known to those skilled in the art.

a) Triazine Synthesis: 2,4-Bis(biphenyl-3-yl)-6-chloro[1,3,5]triazine

(2) ##STR00055##

(3) To an initial charge of 5.2 g of magnesium (0.215 mol) in a 500 ml four-neck flask is slowly added dropwise a solution of 50 g of 3-bromobiphenyl (214 mmol) in 200 ml of THF. The reaction mixture is heated to boiling for 1.5 h and then cooled down to room temperature. An initial charge of cyanuric chloride (17.2 g, 93 mmol) in 150 ml of THF in a second flask is cooled to 0° C. At this temperature, the cooled Grignard reagent is added dropwise and the mixture is stirred at RT for 12 h. After this time, 150 ml of HCl are added to the reaction mixture and the aqueous phase is extracted three times with dichloromethane. The combined organic phases are washed with water, dried over Na.sub.2SO.sub.4 and concentrated. The residue is recrystallized from EtOH. The yield is 32.8 g (78 mmol, 84%).

b) 2-Biphenyl-3-yl-4,6-dichloro[1,3,5]triazine

(4) ##STR00056##

(5) To an initial charge of 7.9 g (330 mmol, 1.2 eq) of magnesium turnings in a 1 l four-neck flask is added a THF solution of 63 g (270 mmol, 1.0 eq) of 3-bromobiphenyl 8a (CAS 2113-57-7) at a sufficiently slow rate to maintain the reflux of the reaction mixture. After the addition has ended, the mixture is heated under reflux for a further 2 h.

(6) In a 2 l four-neck flask, 50 g (270 mmol, 1 eq) of 2,4,6-trichloro-[1,3,5]triazine 7a (CAS 108-77-0) in 500 ml of THF are cooled down to −10° C. At this temperature, the Grignard solution is added dropwise at a sufficiently slow rate that the temperature does not exceed 0° C., and the mixture is finally stirred at room temperature overnight. For workup, 270 ml of 1 N hydrochloric acid are added dropwise and the mixture is stirred for 1 h. Subsequently, the aqueous phase is removed and extracted with diethyl ether. The combined organic phases are dried over sodium sulfate and the solvent is removed on a rotary evaporator. 56 g (69%) of a colourless oil 9a are obtained.

(7) In an analogous manner, it is possible to obtain the following compounds:

(8) TABLE-US-00001 No. Reactant 7 Reactant 8 Product 9 Yield 1b 56% 2b 0 27% 3b 48% 4b 71%

c) 2-Biphenyl-3-yl-4-chloro-6-(9,9′-spirobi-9H-fluoren-2-yl)-[1,3,5]triazine

(9) ##STR00069##
Variant A:

(10) 18 g (50 mmol, 1 eq.) of 9,9-spirobifluoren-2-ylboronic acid 10a (CAS 236389-21-2) together with 15 g (50 mmol, 1 eq.) of 2-biphenyl-3-yl-4,6-dichloro[1,3,5]-triazine 9a and 5.8 g (55 mmol, 1.1 eq.) of sodium carbonate are dissolved in a mixture of 200 ml of dioxane, 200 ml of toluene and 70 ml of water, and the mixture is degassed for 30 minutes. Subsequently, 580 mg (0.50 mmol, 1 mol %) of tetrakis(triphenylphosphine)palladium (CAS 14221-01-3) are added and the mixture is heated at reflux overnight.

(11) The reaction mixture is cooled down and 300 ml of water are added. The aqueous phase is extracted three times with ethyl acetate, the organic phases are combined and the solvent is removed on a rotary evaporator. After hot extraction with heptane/toluene 4:1, 15 g (26 mmol, 51%) of a colourless solid are obtained.

(12) Variant B: Analogous to b)

(13) In an analogous manner, it is possible to obtain the following compounds:

(14) TABLE-US-00002 No. Variant Reactant 9 Reactant 10 Product 11 Yield 1c B 0 68% 2c A 81% 3c A 63% 4c A 0 71% 5c A 53% 8c A 68% 9c B 0 67%

d) 6-Bromo-2-fluoro-2′-methoxybiphenyl

(15) ##STR00091##

(16) 200 g (664 mmol) of 1-bromo-3-fluoro-2-iodobenzene and 101 g (664 mmol) of 2-methoxyphenylboronic acid and 137.5 g (997 mmol) of sodium tetraborate are dissolved in 1000 ml of THF and 600 ml of water, and degassed. 9.3 g (13.3 mmol) of bis(triphenylphosphine)palladium(II) chloride and 1 g (20 mmol) of hydrazinium hydroxide are added. The reaction mixture is then stirred under a protective gas atmosphere at 70° C. for 48 h. The cooled solution is supplemented with toluene, washed repeatedly with water, dried and concentrated. The product is purified via column chromatography on silica gel with toluene/heptane (1:2). Yield: 155 g (553 mmol), 83% of theory.

(17) In an analogous manner, it is possible to obtain the following compounds:

(18) TABLE-US-00003 Reactant 1 Reactant 2 Product Yield d1 77% d2 74% d3 00 76% d4 01 02 03 71%

e) 6′-Bromo-2′-fluorobiphenyl-2-ol

(19) ##STR00104##

(20) 112 g (418 mmol) of 6-bromo-2-fluoro-2′-methoxybiphenyl are dissolved in 2 l of dichloromethane and cooled to 5° C. 41.01 ml (431 mmol) of boron tribromide are added dropwise to this solution within 90 min, and stirring of the mixture continues overnight. Water is added gradually to the mixture, and the organic phase is washed three times with water, dried over Na.sub.2SO.sub.4, concentrated by rotary evaporation and purified by chromatography. Yield: 104 g (397 mmol), 98% of theory.

(21) In an analogous manner, it is possible to obtain the following compounds:

(22) TABLE-US-00004 Reactant 1 Product Yield e1 05 06 92% e2 07 08 90% e3 09 0 93% e4 94%

f) 1-Bromodibenzofuran

(23) ##STR00113##

(24) 111 g (416 mmol) of 6′-bromo-2′-fluorobiphenyl-2-ol are dissolved in 2 l of DMF (max. 0.003% H.sub.2O) SeccoSolv® and cooled to 5° C. 20 g (449 mmol) of sodium hydride (60% suspension in paraffin oil) are added to this solution in portions, once the addition has ended the mixture is stirred for 20 min, and then the mixture is heated to 100° C. for 45 min. After cooling, 500 ml of ethanol are added gradually to the mixture, which is concentrated completely by rotary evaporation and then purified by chromatography. Yield: 90 g (367 mmol), 88.5% of theory.

(25) In an analogous manner, it is possible to obtain the following compounds:

(26) TABLE-US-00005 Reactant 1 Product Yield f1 81% f2 78% f3 73% f4 0 79%

g) Dibenzofuran-1-boronic acid

(27) ##STR00122##

(28) 180 g (728 mmol) of 1-bromodibenzofuran are dissolved in 1500 ml of dry THF and cooled to −78° C. At this temperature, 305 ml (764 mmol/2.5 M in hexane) of n-butyllithium are added within about 5 min, and then the mixture is stirred at −78° C. for a further 2.5 h. At this temperature, 151 g (1456 mmol) of trimethyl borate are added very rapidly and the reaction is allowed to come gradually to RT (about 18 h). The reaction solution is washed with water and the precipitated solids and the organic phase are subjected to azeotropic drying with toluene. The crude product is extracted while stirring from toluene/methylene chloride at about 40° C. and filtered off with suction. Yield: 146 g (690 mmol), 95% of theory.

(29) In an analogous manner, it is possible to obtain the following compounds:

(30) TABLE-US-00006 Reactant 1 Product Yield g1 81% g2 78% g3 73% g4 0 79% g5 73%

h) 2-Dibenzofuran-1-yl-4,6-diphenyl[1,3,5]triazine

(31) ##STR00133##

(32) 23 g (110.0 mmol) of dibenzofuran-1-boronic acid, 29.5 g (110.0 mmol) of 2-chloro-4,6-diphenyl-1,3,5-triazine and 21 g (210.0 mmol) of sodium carbonate are suspended in 500 ml of ethylene glycol diamine ether and 500 ml of water. Added to this suspension are 913 mg (3.0 mmol) of tri-o-tolylphosphine and then 112 mg (0.5 mmol) of palladium(II) acetate, and the reaction mixture is heated under reflux for 16 h. After cooling, the organic phase is removed, filtered through silica gel, washed three times with 200 ml of water and then concentrated to dryness. The residue is recrystallized from toluene and from dichloromethane/heptane. The yield is 37 g (94 mmol), 87% of theory.

(33) In an analogous manner, it is possible to obtain the following compounds:

(34) TABLE-US-00007 Reactant 1 Reactant 2 Product Yield h1 73% h2 82% h3 0 73% h4 72% h5 65% h6 0 63% h14 77% h15 76% h16 0 68%

i) 2-(8-Bromodibenzofuran-1-yl)-4,6-diphenyl[1,3,5]triazine

(35) ##STR00161##

(36) 70 g (190.0 mmol) of 2-dibenzofuran-1-yl-4,6-diphenyl[1,3,5]triazine are suspended in 2000 ml of acetic acid (100%) and 2000 ml of sulfuric acid (95-98%). 34 g (190 mmol) of NBS are added to this suspension in portions and the mixture is stirred in the dark for 2 h. Thereafter, water/ice is added and the solids are removed and washed with ethanol. The residue is recrystallized from toluene. The yield is 80 g (167 mmol), 87% of theory.

(37) In an analogous manner, it is possible to obtain the following compounds:

(38) TABLE-US-00008 Reactant 1 Product Yield i1 80% i2 41% i3 52% i4 64% i5 0 33% i6 41% i7 58%

(39) In the case of thiophene derivatives, nitrobenzene is used rather than sulfuric acid and elemental bromine in place of NBS:

(40) TABLE-US-00009 i8 55%

k) 2,4-Diphenyl-6-[8-(4,4,5,5-tetramethyl[1,3,2]dioxaborolan-2-yl)-dibenzofuran-1-yl][1,3,5]triazine

(41) ##STR00178##

(42) In a 500 ml flask, under protective gas, 13.3 g (28 mmol) of 2-(8-bromodibenzofuran-1-yl)-4,6-diphenyl[1,3,5]triazine and 8.5 g (34 mmol, 1.2 eq) of bis(pinacolato)diborane (CAS 73183-34-3) are dissolved in 120 ml of dry DMF and the mixture is degassed for 30 minutes. Subsequently, 8.2 g (84 mmol, 3.0 eq.) of potassium acetate and 690 mg (0.84 mmol, 3 mol %) of [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) complex with dichloromethane (CAS 95464-05-4) are added, and the mixture is heated to 90° C. overnight. After the reaction has ended, the mixture is diluted with 300 ml of toluene and extracted with water. The residue is recrystallized from heptane. The yield is 15 g (24 mmol), 88% of theory.

(43) In an analogous manner, it is possible to obtain the following compounds:

(44) TABLE-US-00010 Reactant 1 Product Yield k1 0 80% k2 64% k3 63% k4 67% k5 65% k6 0 67% k7 60%

l) 2-[8-(4-Chlorophenyl)dibenzothiophen-1-yl]-4,6-diphenyl[1,3,5]triazine

(45) ##STR00193##

(46) 17.6 g (110.0 mmol) of 4-chlorophenyl-1-boronic acid, 54.3 g (110.0 mmol) of 2-(8-bromodibenzothiophen-1-yl)-4,6-diphenyl[1,3,5]triazine and 21 g (210.0 mmol) of sodium carbonate are suspended in 500 ml of ethylene glycol dimethyl ether and 500 ml of water. Added to this suspension are 913 mg (3.0 mmol) of tri-o-tolylphosphine and then 112 mg (0.5 mmol) of palladium(II) acetate, and the reaction mixture is heated under reflux for 16 h. After cooling, the organic phase is removed, filtered through silica gel, washed three times with 200 ml of water and then concentrated to dryness. The residue is recrystallized from toluene and from dichloromethane/heptane. The yield is 46 g (87 mmol), 81% of theory.

(47) In an analogous manner, it is possible to obtain the following compounds:

(48) TABLE-US-00011 Reactant 1 Reactant 2 Product Yield 1l 73% 2l 82%

m) Biphenyl-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amine

(49) ##STR00200##

(50) 24.0 g (142 mmol, 1.2 eq.) of 4-aminobiphenyl (CAS 92-67-1) and 32.0 g (117 mmol, 1.0 eq.) of 2-bromo-9,9′-dimethylfluorene (CAS 28320-31-2) are initially charged in 950 ml of toluene and saturated with argon for 30 minutes. Subsequently, 1.0 g (1.8 mmol, 0.02 eq.) of 1,1′-bis(diphenylphosphino)ferrocene (CAS 12150-46-8), 350 mg (1.6 mmol, 0.01 eq.) of palladium(II) acetate (CAS 3375-31-3) and 29 g (300 mmol, 2.6 eq.) of sodium tert-butoxide (CAS 865-48-5) are added and the mixture is heated under reflux overnight. After the reaction has ended, the mixture is diluted with 300 ml of toluene and extracted with water. The organic phase is dried over sodium sulfate and the solvent is removed on a rotary evaporator. 50 ml of ethyl acetate are added to the brown oil, which is added to a mixture of heptane/ethyl acetate 20:1. The solids formed are filtered off with suction and washed with heptane. The yield is 29 g (80 mmol), 69% of theory.

(51) In an analogous manner, it is possible to obtain the following compounds:

(52) TABLE-US-00012 Reactant 1 Reactant 2 Product Yield 1m 01 02 03 71% 2m 04 05 06 61% 3m 07 08 09 78% 4m 0 82% 5m 62% 6m 47% 7m 0 92% 8m 75% 9m 84% 10m 0 62% 11m 78% 12m 62%

n) Biphenyl-4-yl-(9,9-dimethyl-9H-fluoren-2-yl)-{4-[9-(4,6-diphenyl-[1,3,5]triazin-2-yl)dibenzofuran-2-yl]phenyl}amine

(53) ##STR00237##

(54) 27.8 g (80 mmol, 1.0 eq.) of biphenyl-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amine and 42 g (80 mmol, 1.0 eq.) of 2-[8-(4-chlorophenyl)dibenzofuran-1-yl]-4,6-diphenyl[1,3,5]triazine are dissolved in 600 ml of toluene and degassed for 30 minutes. Subsequently, 45 g (240 mmol, 3.0 eq.) of sodium tert-butoxide, 890 mg (0.40 mmol, 0.050 eq.) of palladium(II) acetate and 8 ml (8.0 mmol, 0.10 eq.) of a 1M tri-tert-butylphosphine solution are added. The mixture is heated under reflux overnight and, after the reaction has ended, filtered twice through alumina with toluene. After the solvent has been removed on a rotary evaporator, the oil is dissolved in a little THF and introduced into heptane. The residue is recrystallized from toluene and from heptane/toluene 1:1 and finally sublimed under high vacuum (p=5×10.sup.−5 mbar, T=350° C.). The yield is 50 g (59 mmol), 75% of theory.

(55) In an analogous manner, it is possible to obtain the following compounds:

(56) TABLE-US-00013 Reactant 3 Reactant 4 Product Yield 1n 0 69% 2n 64% 3n 59% 4n 61% 5n 0 67% 6n 60% 7n 72%

(57) In an analogous manner, it is possible to obtain the following compounds:

(58) TABLE-US-00014 Reactant 3 Reactant 4 Product Yield 8n 0 51% 9n 37% 10n 80% 11n 0 36% 12n 48% 13n 50% 14n 47%

o) (9,9-Dimethyl-9H-fluoren-4-yl)-(9,9-dimethyl-9H-fluoren-2-yl){7-[9-(4,6-diphenyl[1,3,5]triazin-2-yl)dibenzofuran-2-yl]-9,9-dimethyl-9H-fluoren-2-yl}amine

(59) ##STR00280##

(60) 84 g (125 mmol, 1.0 eq.) of (7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-(9,9-dimethyl-9H-fluoren-4-yl)-(9,9-dimethyl-9H-fluoren-2-yl)amine and 72 g (125 mmol, 1.0 eq) of 2,4-diphenyl-6-[8-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)dibenzofuran-1-yl][1,3,5]triazine are initially charged in a mixture of 400 ml of water, 400 ml of dioxane and 400 ml of toluene, and degassed for 30 minutes. After addition of 280 mg (1.25 mmol, 1 mol %) of palladium(II) acetate and 1.14 g (3.75 mmol, 3 mol %) of tri-o-tolylphoshine, the mixture is heated under reflux overnight and, after the reaction has ended, a little water is added. The organic phase is removed and extracted twice with water. After the organic phase is dried over sodium sulfate, the residue is recrystallized from heptane/toluene. The residue is recrystallized from toluene and from heptane/toluene 1:1 and finally sublimed under high vacuum (p=5×10.sup.−5 mbar, T=350° C.). 96 g (96 mmol, 80%) of a beige solid are obtained.

(61) In an analogous manner, it is possible to obtain the following compounds:

(62) TABLE-US-00015 Reactant 3 Reactant 4 Product Yield o1 51% o2 57% o3 56% o4 0 61% o5 63% o6 57% o7 00 01 62% o8 02 03 04 63% o9 05 06 07 64% o10 08 09 0 60%
Production of the OLEDs

(63) Examples I1 to I12 which follow (see Table 1) present the use of the materials of the invention in OLEDs.

(64) Pretreatment for Examples I1-I12: Glass plaques coated with structured ITO (indium tin oxide) of thickness 50 nm are treated prior to coating with an oxygen plasma, followed by an argon plasma. These plasma-treated glass plaques form the substrates to which the OLEDs are applied.

(65) The OLEDs basically have the following layer structure: substrate/hole injection layer (HIL)/hole transport layer (HTL)/electron blocker layer (EBL)/emission layer (EML)/optional hole blocker layer (HBL)/electron transport layer (ETL)/optional electron injection layer (EIL) and finally a cathode. The cathode is formed by an aluminium layer of thickness 100 nm. The exact structure of the OLEDs can be found in Table 1. The materials required for production of the OLEDs are shown in Table 2.

(66) All materials are applied by thermal vapour deposition in a vacuum chamber. In this case, the emission layer always consists of at least one matrix material (host material) and an emitting dopant (emitter) which is added to the matrix material(s) in a particular proportion by volume by co-evaporation. Details given in such a form as EG3:IC1:TEG1 (59%:29%:12%) mean here that the material EG3 is present in the layer in a proportion by volume of 59%, IC1 in a proportion of 29% and TEG1 in a proportion of 12%. Analogously, the electron transport layer may also consist of a mixture of two materials.

(67) The OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectra, the current efficiency (measured in cd/A) and the external quantum efficiency (EQE, measured in percent) are determined as a function of luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming Lambertian emission characteristics. The voltage, current efficiency and external quantum efficiency are reported for a luminance of 1000 cd/m.sup.2. The electroluminescence spectra are determined at a luminance of 1000 cd/m.sup.2, and the CIE 1931 x and y colour coordinates are calculated therefrom.

(68) The lifetime LT_L1 is defined as the time after which the luminance drops from the starting luminance to a certain proportion L1 in the course of operation with constant current. LD_80 is thus the time within which the luminance drops to 80% of its starting value in operation. In the examples listed below, a current density of 40 mA/cm.sup.2 is used as an operating condition.

(69) Use of Materials of the Invention in OLEDs

(70) The inventive compounds EG1 to EG12 are used in Examples I1 to I12 as matrix material in the emission layer. The colour coordinates of the electroluminescence spectra of the OLEDs from these experiments are CIEx=0.3 and CIEy=0.6. The materials are thus suitable for use in the emission layer of phosphorescent green OLEDs.

(71) With the OLED of the invention in Example 11, the following device data are obtained:

(72) Voltage: 3.2 V

(73) Current efficiency: 62 cd/A

(74) EQE: 17%

(75) LD_80: 160 h

(76) Comparable device data are obtained with the OLEDs of the invention in examples I2 to I12.

(77) TABLE-US-00016 TABLE 1 Structure of the OLEDs HIL HTL EBL EML ETL Ex. thickness thickness thickness thickness HBL thickness I1 HATCN SpMA1 SpMA3 EG3:IC1:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (59%:29%:12%) (50%:50%) 30 nm 40 nm I2 HATCN SpMA1 SpMA3 EG1:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (95%:5%) (50%:50%) 30 nm 40 nm I3 HATCN SpMA1 SpMA3 EG2:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (95%:5%) (50%:50%) 30 nm 40 nm I4 HATCN SpMA1 SpMA3 EG3:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (95%:5%) (50%:50%) 30 nm 40 nm I5 HATCN SpMA1 SpMA3 EG4:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (95%:5%) (50%:50%) 30 nm 40 nm I6 HATCN SpMA1 SpMA3 EG5:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (95%:5%) (50%:50%) 30 nm 40 nm I7 HATCN SpMA1 SpMA3 EG6:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (95%:5%) (50%:50%) 30 nm 40 nm I8 HATCN SpMA1 SpMA3 EG7:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (95%:5%) (50%:50%) 30 nm 40 nm I9 HATCN SpMA1 SpMA3 EG8:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (95%:5%) (50%:50%) 30 nm 40 nm  I10 HATCN SpMA1 SpMA3 EG9:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (95%:5%) (50%:50%) 30 nm 40 nm  I11 HATCN SpMA1 SpMA3 EG10:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (95%:5%) (50%:50%) 30 nm 40 nm  I12 HATCN SpMA1 SpMA3 EG11:TEG1 — ETM1:LiQ 5 nm 230 nm 20 nm (95%:5%) (50%:50%) 30 nm 40 nm

(78) TABLE-US-00017 TABLE 2 Structural formulae of the materials for the OLEDs 0