Materials for organic electroluminescent devices

Abstract

The present invention relates to compounds of the formula (1) which are suitable for use in electronic devices, in particular organic electroluminescent devices, and to electronic devices which comprise these compounds. ##STR00001##

Claims

1. A compound of formula (1): ##STR00227## wherein Ar.sup.1 is on each occurrence, identically or differently, an aryl or heteroaryl group having 6 to 18 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R.sup.1, wherein at least one Ar.sup.1 has 10 or more aromatic ring atoms; Ar.sup.2 is on each occurrence, identically or differently, an aryl or heteroaryl group having 6 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R.sup.1; Ar.sup.3 and Ar.sup.4 are on each occurrence, identically or differently, an aromatic or heteroaromatic ring systems having 5 to 25 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R.sup.1; wherein at least one Ar.sup.3 is a group of formula (Ar3-2) and/or at least one Ar.sup.4 is a group of formula (Ar4-2): ##STR00228## wherein the dashed bonds in the group of formula (Ar3-2) indicate the bonding to Ar.sup.1 and to a group Ar.sup.3 or Ar.sup.4; the dashed bond in the group of formula (Ar4-2) indicates the bonding to Ar.sup.3; E.sup.1 stands for —C(R.sup.0).sub.2; and the groups of formulae (Ar3-2) and (Ar4-2) are optionally substituted at each free position by a group R.sup.1; E is identically or differently on each occurrence, selected from the group consisting of —BR.sup.0—, —C(R.sup.0).sub.2—, —C(R.sup.0).sub.2—C(R.sup.0).sub.2—, —C(R.sup.0).sub.2—O—, C(R.sup.0).sub.2—S—, —R.sup.0C═CR.sup.0—, —R.sup.0C═N—, —Si(R.sup.0).sub.2—, —Si(R.sup.0).sub.2—Si(R.sup.0).sub.2—, —C(═O)—, —C(═NR.sup.0)—, —C(═C(R.sup.0).sub.2—, —O—, —S—, —S(═O)—, —SO.sub.2—, —N(R.sup.0)—, —P(R.sup.0)—, and —P((═O)R.sup.0)—, wherein two groups E are optionally in a cis or trans position relative to each other; R.sup.0 and R.sup.1 are on each occurrence, identically or differently, H, D, F, Cl, Br, I, CHO, CN, N(Ar.sup.5).sub.2, C(═O)Ar.sup.5, P(═O)(Ar.sup.5).sub.2, S(═O)Ar.sup.5, S(═O).sub.2Ar.sup.5, NO.sub.2, Si(R.sup.2).sub.3, B(OR.sup.2).sub.2, OSO.sub.2R.sup.2, a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R.sup.2, wherein in each case one or more non-adjacent CH.sub.2 groups are optionally replaced by R.sup.2C═CR.sup.2, C≡C, Si(R.sup.2).sub.2, Ge(R.sup.2).sub.2, Sn(R.sup.2).sub.2, C═O, C═S, C═Se, P(═O)(R.sup.2), SO, SO.sub.2, O, S, or CONR.sup.2 and wherein one or more H atoms is optionally replaced by D, F, Cl, Br, I, CN, or NO.sub.2, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R.sup.2, or an aryloxy group having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.2, and wherein two adjacent substituents R.sup.0 and/or two adjacent substituents R.sup.1 optionally define a mono- or polycyclic, aliphatic ring system or aromatic ring system, which is optionally substituted by one or more radicals R.sup.2; R.sup.2 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, CHO, CN, N(Ar.sup.5).sub.2, C(═O)Ar.sup.5, P(═O)(Ar.sup.5).sub.2, S(═O)Ar.sup.5, S(═O).sub.2Ar.sup.5, NO.sub.2, Si(R.sup.3).sub.3, B(OR.sup.3).sub.2, OSO.sub.2R.sup.3, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R.sup.3, wherein in each case one or more non adjacent CH.sub.2 groups is optionally replaced by R.sup.3C═CR.sup.3, C≡C, Si(R.sup.3).sub.2, Ge(R.sup.3).sub.2, Sn(R.sup.3).sub.2, C═O, C═S, C═Se, P(═O)(R.sup.3), SO, SO.sub.2, O, S, or CONR.sup.3 and wherein one or more H atoms is optionally replaced by D, F, Cl, Br, I, CN, or NO.sub.2, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R.sup.3, or an aryloxy group having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.3, and where two adjacent substituents R.sup.2 optionally define a mono- or polycyclic, aliphatic ring system or aromatic ring system, which is optionally substituted by one or more radicals R.sup.3; R.sup.3 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, CN, a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 20 C atoms, wherein in each case one or more non adjacent CH.sub.2 groups is optionally replaced by SO, SO.sub.2, O, or S and wherein one or more H atoms is optionally replaced by D, F, Cl, Br, or I, or an aromatic or heteroaromatic ring system having 5 to 24 C atoms; Ar.sup.5 is an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R.sup.3; n is an integer from 2 to 20.

2. The compound of claim 1, wherein n is an integer from 2 to 8.

3. The compound of claim 1, wherein the compound of formula (1) contains at least one group R.sup.0 or R.sup.1 that is a straight-chain alkyl group having 2 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R.sup.2.

4. The compound of claim 1, wherein the compound of formula (1) is selected from the group consisting of compounds of formula (1-1) and formula (1-2): ##STR00229## wherein V is on each occurrence, identically or differently, CR.sup.1 or N, wherein V is C when V is bonded to a group Ar.sup.3 or to a group E.

5. The compound of claim 4, wherein the compound of formula (1) is selected from the group consisting of compounds of formulae (1-1-1) to (1-1-11) and (1-2-1) to (1-2-7): ##STR00230## ##STR00231##

6. The compound of claim 4, wherein the compound of formula (1) is selected from the group consisting of compounds of formulae (1-1-1-a) to (1-1-11-a) and (1-2-1-a) to (1-2-7-a): ##STR00232## ##STR00233##

7. The compound of claim 1, wherein Ar.sup.3 is selected from the group consisting of formulae (Ar3-1) to (Ar3-25): ##STR00234## ##STR00235## ##STR00236## ##STR00237## wherein the dashed bonds indicate the bonding to Ar.sup.1 and to a group Ar.sup.3 or Ar.sup.4; the groups of formulae (Ar3-1) to (Ar3-25) are optionally substituted at each free position by a group R.sup.1; and E.sup.1 is selected from the group consisting of —B(R.sup.0−), —C(R.sup.0).sub.2−, —C(R.sup.0).sub.2—C(R.sup.0).sub.2—, —Si(R.sup.0).sub.2—, —C(═O)—, —C(═NR.sup.0)—, —C═(C(R.sup.0).sub.2—, —O—, —S—, —S(═O)—, —N(R.sup.0)—, —P(R.sup.0)—, and P((═O)R.sup.0—.

8. The compound of claim 1, wherein Ar.sup.4 is selected from the group consisting of formulae (Ar4-1) to (Ar4-27): ##STR00238## ##STR00239## ##STR00240## ##STR00241## wherein the dashed bond indicates the bonding to Ar.sup.3; E.sup.1 is selected from the group consisting of —B(R.sup.0−), —C(R.sup.0).sub.2—, —C(R.sup.0).sub.2—C(R.sup.0).sub.2—, —Si(R.sup.0).sub.2—, —C(═O)—, —C(═NR.sup.0)—, —C═(C(R.sup.0).sup.2—, —O—, —S—, —S(═O)—, —N(R.sup.0)—, —P(R.sup.0)—, and —P((═O)R.sup.0)—.

9. The compound of claim 1, wherein at least one group AP is a group of formula (Ar3-2-1) and/or at least one group Ar.sup.4 is a group of formula (Ar4-2-1): ##STR00242## wherein the dashed bonds in the group of formula (Ar3-2-1) indicate the bonding to Ar.sup.1 and to a group Ar.sup.3 or Ar.sup.4; the dashed bond in the group of formula (Ar4-2-1) indicates the bonding to Ar.sup.3; E.sup.1 is —C(R.sup.0).sub.2—; and the groups of formulae (Ar3-2-1) and (Ar4-2-1) are optionally substituted at each free position by a group R.sup.1.

10. The compound of claim 1, wherein at least one group Ar.sup.3 is a group of formula (Ar3-2-1b) and/or at least one group Ar.sup.4 is a group of formula (Ar4-2-1b): ##STR00243## wherein the dashed bonds in the group of formula (Ar3-2-1b) indicate the bonding to A.sup.1 and to a group Ar.sup.3 or Ar.sup.4; the dashed bonds in the group of formula (Ar4-2-1b) indicates the bonding to Ar.sup.3; and the groups of formulae (Ar3-2-1b) and (Ar4-2-1b) are optionally substituted at each free position by a group R.sup.1.

11. The compound of claim 1, wherein E is, identically or differently, on each occurrence, selected from the group consisting of —C(R.sup.0).sub.2—, —C(R.sup.0).sub.2—C(R.sup.0).sub.2—, —O—, —S—, and —N(R.sup.0)—.

12. The compound of claim 1, wherein E is —C(R.sup.0).sub.2—.

13. The compound of claim 1, wherein R.sup.0 is on each occurrence, identically or differently, H, D, F, CN, Si(R.sup.2).sub.3, a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, each of which is optionally substituted by one or more radicals R.sup.2, wherein in each case one or more H atoms is optionally replaced by F, or an aryl or heteroaryl group having 5 to 40 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R.sup.2, and wherein two adjacent substituents optionally define a mono- or polycyclic, aliphatic ring system or aromatic ring system, which is optionally substituted by one or more radicals R.sup.2.

14. An oligomer, polymer, or dendrimer comprising one or more compounds of claim 1, where the one or more compounds is bonded to the polymer, oligomer, or dendrimer at any position in formula (1) substituted by R.sup.1.

15. A formulation comprising at least one compound of claim 1 and at least one solvent.

16. A formulation comprising at least one oligomer, polymer, or dendrimer of claim 14 and at least one solvent.

17. An electronic device comprising at least one compound of claim 1, wherein the electronic device is selected from the group consisting of organic electroluminescent devices, organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic solar cells, dye-sensitised organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, light-emitting electrochemical cells, organic laser diodes, and organic plasmon emitting devices.

18. An electronic device comprising at least one oligomer, polymer, or dendrimer of claim 14, wherein the electronic device is selected from the group consisting of organic electroluminescent devices, organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic solar cells, dye-sensitised organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, light-emitting electrochemical cells, organic laser diodes, and organic plasmon emitting devices.

19. The electronic device of claim 17, wherein the electronic device is an organic electroluminescent device and the at least one compound is employed as a fluorescent emitter or as a matrix material for fluorescent emitters.

20. The electronic device of claim 18, wherein the electronic device is an organic electroluminescent device and the at least one oligomer, polymer, or dendrimer is employed as a fluorescent emitter or as a matrix material for fluorescent emitters.

Description

WORKING EXAMPLES

A) Synthesis Examples

A-1)

(1) Synthesis Scheme:

(2) ##STR00163##

(3) TABLE-US-00001 Com- pound Synthesis/ Yield Int-a1 commercially available CAS 198964-46-4

(4) ##STR00166##

(5) 2,7-Dibromo-9,9-dioctyl-9H-fluorene (100 g, 0.17 mol), bis(pinacolato)diboron (94.9 g, 0.37 mol) and potassium acetate (50 g, 0.51 mol) were suspended in 1.4 L dioxane. The solution was saturated with argon. PdCl.sub.2(dppf)-CH.sub.2Cl.sub.2 (4.2 g, 0.01 mol) was added. The reaction mixture was refluxed for sixteen hours and then cooled to room temperature. Ethyl acetate and water were added. The organic phase was washed with water (3×500 mL). The organic phase was concentrated under reduced pressure and the residue was purified by recrystallization from ethanol. Yield: 98 g (90%). Purity>95% (NMR in CDCl.sub.3).

(6) ##STR00167##

(7) Step 1: 2,7-Bispinacolato-9,9-dioctyl-9H-fluoren (94 g, 0.146 mol), 1-bromnaphthaline-2-ethyl ester (104 g, 0.37 mmol) and sodium carbonate (56 g, 0.5 mol) were added to water/toluene/dioxane (1:1:1, 1.5 L). The solution was saturated with argon. Tetrakis(triphenylphosphin)-palladium(0) (15.2 g, 0.01 mol) was added and the reaction mixture was refluxed for 6 hours. After cooling down to room temperature toluene (500 mL) was added and the organic phase was washed with water (3×500 mL) and then concentrated under reduced pressure. The residue was purified by recrystallization from ethanol. Yield: 115 g (0.145 mol; 99%). Purity>95% (NMR, CDCl.sub.3)

(8) Step 2: 115 g (0.145 mol) of the intermediate (Step 1) diluted in 1 L THF were added 145 g (0.60 mol) cerium(III) chloride and 500 ml THF and the mixture was stirred for 30 minutes and cooled to 0° C. 390 ml (1.17 mol) methylmagnesiumchloride (3M in THF) was added dropwise to the reaction mixture at 0° C. The reaction mixture was allowed to warm to room temperature. After 16 hours 800 ml sat. aq. ammonium chloride was added at 0° C. Ethyl acetate (2×500 mL) was added, the combined organic phases were washed with water (2×500 mL) and concentrated under reduced pressure. The residue was purified by recrystallization from ethanol. Yield: 103 g (0.146 mol, 93%).

(9) Step 3: 103 g (0.14 mol) of the intermediate (Step 2) were solved in 1.5 L toluene and 275 g amberlyst 15 were added. The reaction mixture was refluxed for 16 hours using a Dean-Stark apparatus. After cooling down to room temperature amberlyst was removed by filtration and the organic phase was concentrated under reduced pressure. The residue was purified by several recrystallizations from ethanol or heptane/toluene.

(10) Yield: 73 g (0.101 mol; 75%).

(11) ##STR00168##

(12) Ia (73 g, 101 mmol) was dissolved in 1 L DCM and cooled to −10° C. Br.sub.2 (33.1 g, 207 mmol) in 500 ml DCM was added dropwise. The reaction mixture was stirred one hour at 0° C. and then allowed to warm to room temperature. After 16 hours, 20 ml aqueous, saturated sodium thiosulfate solution was added and the mixture was stirred for 15 minutes. Water (1 L) was added, the organic phase was washed with water (3×500 mL) and the combined organic phases were concentrated under reduced pressure. The residue was purified by several recrystallizations from ethanol or heptane/toluene.

(13) Yield: 66.4 g (75 mmol; 74%)

Synthesis of Compound B

(14) Compound B can be synthesized in an analogous manner to Int-B:

(15) ##STR00169##

Synthesis of Compound C1

(16) ##STR00170##

(17) 30 g (97.5 mmol) 2-Bromo-7-Chloro-9,9-dimethyl-9H-fluorene (see JP 2003277305 A), 25.5 g (107.3 mmol) (9,9-dimethylfluoren-2-yl)boronic acid 90 g (390 mmol), 0.9 g (4 mmol) palladium(II)acetate and 3.6 g (11.7 mmol) tri(o-tolyl)-phosphine were dissolved in 1 L toluene, dioxane, water (1:1:1) and stirred at reflux overnight. After cooling down to room temperature 200 ml toluene were added and the organic phase was separated and washed with water (2×200 ml) and the combined organic phases were concentrated under reduced pressure. The residue was purified by recrystallization from toluene/heptane.

(18) Yield: 39.1 g (93 mmol; 96%)

(19) Following compounds can be synthesized in an analogous manner:

(20) TABLE-US-00002 Com- pound Starting material Product Yield C2 89% C3 78%

Synthesis of D1

(21) ##STR00175##

(22) 40 g (95 mmol) C1, 38.6 g (152 mmol) bis-(pinacolato)-diboron, 4.2 g (5.7 mmol) trans-dichloro(tricyclohexylphosphine)palladium(II) and 28 g (285 mmol) potassium acetate were dissolved in 400 ml dioxane and stirred for 16 h at reflux. The reaction mixture was allowed to cool to room temperature and 400 ml toluene were added. The organic phase was separated, washed with water (2×200 mL) and filtered through Celite. The solution was concentrated to dryness under reduced pressure. The residue was purified by recrystallization from toluene/heptane.

(23) Yield: 36 g (70 mmol; 74%)

(24) Following compounds can be synthesized in an analogous manner:

(25) TABLE-US-00003 com- Starting pound material Product Yield D2 C2 89% D3 C3 87%

Synthesis of E1

(26) ##STR00178##

(27) 5.5 g (17.8 mmol) 2-Bromo-5-iodo-1,3-dimethylbenzene, 6.5 g (12.7 mmol) D1, 366 mg (0.3 mmol) tetrakis(triphenylphosphin)-palladium(0) and 2.7 g (13 mmol) sodium carbonate were dissolved in 200 ml toluene, ethanol and water (2:1:1) and stirred for 16 hours at 90° C. After cooling down to room temperature 100 ml toluene were added, the organic phase was separated and washed with water (2×50 ml). The organic phase was concentrated to dryness under reduced pressure. The residue was purified by recrystallization from toluene/heptane.

(28) Yield: 6.2 g (11 mmol; 86%)

(29) The following compounds can be synthesized in an analogous manner:

(30) TABLE-US-00004 Starting Starting Com- material material pound A B Product Yield E2 D2 CAS 689260-53-5 89% E3 D2 CAS 699119-05-6 0 87% E4 D1 CAS 699119-05-6 83% E5 D2 CAS 844856-42-4 85% E6 D1 CAS 844856-42-4 81% E7 D2   see JP 20032 77305 A 78% E8 D3 CAS 689260-53-5 82% E9 D2 CAS 637-87-6 87% E10 D2 CAS 23055-77-8 78%

Synthesis of Compounds F

(31) Compounds F can be synthesized in an analogous manner to E1:

(32) TABLE-US-00005 Starting Starting Com- material material pound A B Product Yield F1 CAS 1679- 18-1 E1 68% F2 CAS 1679- 18-1 E2 0 67% F3 CAS 1679- 18-1 E3 72% F4 CAS 1679- 18-1 E4 69% F5 CAS 1679- 18-1 E8 72%

Synthesis of Compounds G

(33) Compounds G can be synthesized in an analogous manner to D1:

(34) TABLE-US-00006 Com- Starting pound material Product Yield G1 E5 82% G2 E6 79% G3 F1 78% G4 F2 81% G5 F3 83% G6 F4 70% G7 E7 00 72% G9 F5 01 69% G10 E9 02 73% G11 E10 03 81%

(35) ##STR00204##

(36) Int-c (18.7 g, 21.2 mmol), 4-biphenylboronic acid (9.25 g, 46.7 mmol) and sodium carbonate (4.5 g, 42.4 mmol) were dissolved in a mixture of toluene, ethanol and water (2:1:1) and the solution was saturated with argon. Tetrakis(triphenylphosphine)-palladium(0) (613 mg, 0.53 mmol) was added and stirred for 6 hours at 110° C. The reaction mixture was allowed to cool to room temperature, toluene (400 mL) and water (200 mL) were added and the organic phase was separated and washed twice with water (400 mL). The organic phase was concentrated under reduced pressure. The residue was further purified by filtration through silica (eluting with toluene), recrystallization from heptane/toluene.

(37) Yield: 13.3 g (12.9 mmol; 61%)

(38) Following compounds IIb to IIm can be synthesized in an analogous manner:

(39) TABLE-US-00007 Start- ing mate- rial A Start- ing mate- rial B 05 Yield IIb Int- C1 D1 06 52% IIc Int- C1 G5 07 58 % IId Int- C1 G4 08 62% IIe Int- C1 G1 09 63% IIf Int- C1 G6 0 59% IIg Int- C1 G3 57% IIh Int- C1 G2 55% IIi Int- C1 G7 54% IIj Int- C1 C 58% IIk Int- C1 G9 57% IIl Int- C1 G10 62% IIm Int- C1 G11 67%

B) Device Examples

B-1) Device Examples Processed from Solution: Production of OLEDs

(40) The production of solution-based OLEDs is described in principle in the literature, for example in WO2004/037887 and WO 2010/097155. In the following examples, the two production methods (application from gas phase and solution processing) were combined, so that processing up to and including the emission layer was carried out from solution and the subsequent layers (hole-blocking layer/electron-transport layer) were applied by vacuum vapour deposition. The general processes described above are for this purpose adapted to the circumstances described here (layer-thickness variation, materials) and combined as follows.

(41) The device structure used is thus as follows: substrate, ITO (50 nm), PEDOT (20 nm), hole-transport layer (HTL) (20 nm), emission layer (92% of host, 8% of dopant) (60 nm), electron-transport layer (ETL) (20 nm), electron-injection layer (EIL) (3 nm) cathode (Al) (100 nm).

(42) The substrates used are glass plates coated with structured ITO (indium tin oxide) in a thickness of 50 nm. For better processing, these are coated with the buffer (PEDOT) Clevios P VP AI 4083 (Heraeus Clevios GmbH, Leverkusen). The spin coating of the buffer is carried out from water in air. The layer is subsequently dried by heating at 180° C. for 10 minutes. The hole-transport and emission layers are applied to the glass plates coated in this way.

(43) The hole-transport layer is the polymer of the structure shown in Table 2, which was synthesised in accordance with WO 2010/097155. The polymer is dissolved in toluene, so that the solution typically has a solid content of approx. 5 g/I if, as here, the layer thickness of 20 nm which is typical for a device is to be achieved by means of spin coating. The layers are applied by spin coating in an inert-gas atmosphere, in the present case argon, and dried by heating at 180° C. for 60 min.

(44) The emission layer (EML) is always composed of at least one matrix material (host=H) and an emitting dopant (emitter=D). An expression such as H1 (92%):D1 (8%) here means that material H1 is present in the emission layer in a proportion by weight of 92% and dopant D1 is present in the emission layer in a proportion by weight of 8%. The mixture for the emission layer is dissolved in toluene. The typical solid content of such solutions is approx. 18 g/I if, as here, the layer thickness of 60 nm which is typical for a device is to be achieved by means of spin coating. The layers are applied by spin coating in an inert-gas atmosphere, in the present case argon, and dried by heating at 140° C. for 10 minutes. The materials used are shown in Table 2.

(45) The materials for the electron-transport layer, the electron-injection layer and for the cathode are applied by thermal vapour deposition in a vacuum chamber. The electron-transport layer, for example, may consist of more than one material, which are admixed with one another in a certain proportion by volume by co-evaporation. An expression such as ETM:EIL (50%:50%) would mean that materials ETM and EIL are present in the layer in a proportion by volume of 50% each. The materials used in the present case are shown in Table 2.

(46) The OLEDs are characterised by standard methods. For this purpose, the electroluminescence spectra are recorded, the current efficiency (measured in cd/A) and the external quantum efficiency (EQE, measured in percent) as a function of the luminous density assuming Lambert emission characteristics are calculated from current/voltage/luminous density characteristic lines (IUL characteristic lines), and finally the lifetime of the components is determined. The electroluminescence spectra are recorded at a luminous density of 1000 cd/m.sup.2, and the CIE 1931 x and y colour coordinates are calculated from this data. The term EQE @ 1000 cd/m.sup.2 denotes the external quantum efficiency at an operating luminous density of 1000 cd/m.sup.2. The lifetime LD80 @ 10 mA/cm.sup.2 is the time which passes until the initial luminance at a driving current density of 10 mA/cm.sup.2 has dropped by 20%. The data obtained for the various OLEDs are summarised in Table 1.

(47) Use of Compounds According to the Invention as Fluorescent Emitter Materials in Organic Light Emitting Diodes

(48) The compounds according to the invention are particularly suitable as emitter materials in blue-fluorescent OLEDs. Emitters D1, D2, D3 and D4 are shown as compounds according to the invention. The state-of-the-art compound for comparison is represented by V-D1 and V-D2. All emitters are used in combination with either host H1 or H2.

(49) Examples E1 to E8 show in a comparative examination with Comparative Examples V1 and V2 that compounds D1, D2, D3 and D4 according to the invention achieve an improved external quantum efficiency (EQE) and an increased lifetime (LD80) with deep-blue emission as compared to comparative material V-D1 and V-D2. Especially the comparison of material V-D1 (Device V1 and V2) with D3 (Example E5) and D4 (Example E6) shows the technical effect of the present invention, in which an expansion of the Bis-Indenofluorene-Core leads to an improved device performance compared to the state-of-the-art while maintaining the same deep blue color.

(50) TABLE-US-00008 TABLE 1 Data of the OLEDs EQE@ LD80@ 1000 10 mA/ Host Emitter cd/m.sup.2 cm.sup.2 CIE Example 92% 8% % [h] x y V1 H1 V-D1 2.9 140 0.144 0.132 V2 H2 V-D1 3.2 150 0.142 0.138 V3 H1 V-D2 3.1 150 0.144 0.129 V4 H2 V-D2 3.3 160 0.147 0.134 E1 H1 D1 4.1 200 0.146 0.158 E2 H2 D1 4.3 220 0.138 0.164 E3 H1 D2 4.5 220 0.139 0.162 E4 H2 D2 4.6 230 0.137 0.165 E5 H2 D3 4.5 190 0.142 0.130 E6 H1 D4 4.3 210 0.144 0.128

(51) TABLE-US-00009 TABLE 2 Structures of the materials used 0

(52) Compounds according to the invention possess decent solubility and thus are well suitable for solution processing. By this technique, electronic devices based on blue fluorescent emitters with excellent performance data can be generated.

(53) Alternatively, or in addition, the compounds according to the invention may serve as host materials inside the emission layer (EML), as hole injection material (HIL), as hole transporting material (HTL), as electron transporting material (ETL) or as electron-injection material (EIL) in an organic light emitting diode.