AROMATIC COMPOUNDS FOR ORGANIC ELECTROLUMINESCENT DEVICES

Abstract

The invention relates to compounds which are suitable for use in electronic devices, and to electronic devices, in particular organic electroluminescent devices, containing said compounds.

Claims

1.-19. (canceled)

20. A compound including at least one structure of the formula (Ia) and/or (Ib): ##STR00332## where the symbols and indices used are as follows: Z.sup.1, Z.sup.2 is the same or different at each instance and is N, P, B, Al, P(═O), P(═S), or Ga; Y.sup.1, Y.sup.2, Y.sup.3 is the same or different at each instance and is a bond, N(Ar), N(R), P(Ar), P(R), P(═O)Ar, P(═O)R, P(═S)Ar, P(═S)R, B(Ar), B(R), Al(Ar), Al(R), Ga(Ar), Ga(R), C═O, C(R).sub.2, Si(R).sub.2, C═NR, C═NAr, C═C(R).sub.2, O, S, Se, S═O, or SO.sub.2; p.sup.2, p.sup.3 are the same or different and are 0 or 1; X is N, CR, or C if a Y.sup.1, Y.sup.2 or Y.sup.3 group binds thereto, with the proviso that not more than two of the X groups in one cycle are N; R is the same or different at each instance and is H, D, OH, F, Cl, Br, I, CN, NO.sub.2, N(Ar).sub.2, N(R.sup.1).sub.2, C(═O)N(Ar).sub.2, C(═O)N(R.sup.1).sub.2, C(Ar).sub.3, C(R.sup.1).sub.3, Si(Ar).sub.3, Si(R.sup.1).sub.3, B(Ar).sub.2, B(R.sup.1).sub.2, C(═O)Ar, C(═O)R.sup.1, P(═O)(Ar).sub.2, P(═O)(R.sup.1).sub.2, P(Ar).sub.2, P(R.sup.1).sub.2, S(═O)Ar, S(═O)R.sup.1, S(═O).sub.2Ar, S(═O).sub.2R.sup.1, OSO.sub.2Ar, OSO.sub.2R.sup.1, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or an alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 carbon atoms, where the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group may in each case be substituted by one or more R.sup.1 radicals, where one or more non-adjacent CH.sub.2 groups may be replaced by R.sup.1C═CR.sup.1, Si(R.sup.1).sub.2, C═O, C═S, C═Se, C═NR.sup.1, —C(═O)O—, —C(═O)NR.sup.1—, NR.sup.1, P(═O)(R.sup.1), —O—, —S—, SO or SO.sub.2, or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and may be substituted in each case by one or more R.sup.1 radicals, or an aryloxy or heteroaryloxy group which has 5 to 60 aromatic ring atoms and may be substituted by one or more R.sup.1 radicals; at the same time, two R radicals may also together form a ring system; Ar is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and may be substituted by one or more R.sup.1 radicals; at the same time, it is possible for two Ar radicals bonded to the same carbon atom, silicon atom, nitrogen atom, phosphorus atom or boron atom also to be joined together via a bridge by a single bond or a bridge selected from B(R.sup.1), C(R.sup.1).sub.2, Si(R.sup.1).sub.2, C═O, C═NR.sup.1, C═C(R.sup.1).sub.2, O, S, S═O, SO.sub.2, N(R.sup.1), P(R.sup.1) and P(═O)R.sup.1; R.sup.1 is the same or different at each instance and is H, D, F, Cl, Br, I, CN, NO.sub.2, N(Ar′).sub.2, N(R.sup.2).sub.2, C(═O)Ar′, C(═O)R.sup.2, P(═O)(Ar′).sub.2, P(Ar′).sub.2, B(Ar′).sub.2, B(R.sup.2).sub.2, C(Ar′).sub.3, C(R.sup.2).sub.3, Si(Ar′).sub.3, Si(R.sup.2).sub.3, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 carbon atoms or an alkenyl group having 2 to 40 carbon atoms, each of which may be substituted by one or more R.sup.2 radicals, where one or more non-adjacent CH.sub.2 groups may be replaced by —R.sup.2C═CR.sup.2—, —C≡C—, Si(R.sup.2).sub.2, C═O, C═S, C═Se, C═NR.sup.2, —C(═O)O—, —C(═O)NR.sup.2—, NR.sup.2, P(═O)(R.sup.2), —O—, —S—, SO or SO.sub.2 and where one or more hydrogen atoms may be replaced by D, F, Cl, Br, I, CN or NO.sub.2, or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms, each of which may be substituted by one or more R.sup.2 radicals, or an aryloxy or heteroaryloxy group which has 5 to 60 aromatic ring atoms and may be substituted by one or more R.sup.2 radicals, or an aralkyl or heteroaralkyl group which has 5 to 60 aromatic ring atoms and may be substituted by one or more R.sup.2 radicals, or a combination of these systems; at the same time, two or more, preferably adjacent R.sup.1 radicals together may form a ring system; at the same time, one or more R.sup.1 radicals may form a ring system with a further part of the compound; Ar′ 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 R.sup.2 radicals; at the same time, it is possible for two Ar′ radicals bonded to the same carbon atom, silicon atom, nitrogen atom, phosphorus atom or boron atom also to be joined together via a bridge by a single bond or a bridge selected from B(R.sup.2), C(R.sup.2).sub.2, Si(R.sup.2).sub.2, C═O, C═NR.sup.2, C═C(R.sup.2).sub.2, O, S, S═O, SO.sub.2, N(R.sup.2), P(R.sup.2) and P(═O)R.sup.2; R.sup.2 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 20 carbon atoms or an aromatic or heteroaromatic ring system which has 5 to 30 aromatic ring atoms and in which one or more hydrogen atoms may be replaced by D, F, Cl, Br, I or CN and which may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms; or two or more substituents R.sup.2 together may form a ring system.

21. A compound as claimed in claim 20, comprising at least one structure of the formulae (IIa), (IIb), (IIc) and (IId): ##STR00333## where p.sup.2, p.sup.3, Y.sup.1, Y.sup.2, Y.sup.3, X, Z.sup.1, Z.sup.2 and R have the definitions given in claim 20, the index n is 0, 1, 2 or 3, the index j is 0, 1 or 2, and the index k is 0 or 1, where the sum total of the indices k, j and n is 0, 1, 2, 3, 4, 5 or 6.

22. A compound as claimed in claim 20, selected from the compounds of the formulae (IIIa), (IIIb), (IIIc) and (IIId): ##STR00334## where Y.sup.2, Y.sup.3, X, Z.sup.1, Z.sup.2 and R have the definitions given in claim 20, the index 1 is 0, 1, 2, 3, 4 or 5, the index m is 0, 1, 2, 3 or 4, and the index n is 0, 1, 2 or 3, where the sum total of the indices 1, m and n is 2, 3, 4, 5, 6, 7 or 8, preference being given to structures of the formulae (IIIa) and (IIIb).

23. A compound as claimed in claim 20, wherein, if Z.sup.1 is N and Y.sup.1 is N(Ar), compounds are excluded in which the Ar group of the N(Ar) radical represented by Y.sup.1, together with four R radicals derived from X groups of the ring systems to which the Y.sup.1 radical binds, forms an aromatic ring system where any two of the four X groups are adjacent.

24. A compound as claimed in claim 20, wherein Z.sup.1 is selected from N and P and the Y.sup.1 group is P(═O)Ar, P(═O)R, B(Ar), B(R), Al(Ar), Al(R), Ga(Ar), Ga(R), C═O, S═O or SO.sub.2, or that Z.sup.1 is selected from N and P and the Z.sup.2 group is B, Al, P(═O), P(═S) or Ga, or that Z.sup.2 is selected from N and P and at least one of the Y.sup.2, Y.sup.3 groups is P(═O)Ar, P(═O)R, B(Ar), B(R), Al(Ar), Al(R), Ga(Ar), Ga(R), C═O, S═O or SO.sub.2.

25. A compound as claimed in claim 20, wherein Z.sup.2 is selected from B, Al, P(═O), P(═S) and Ga and the Y.sup.1 group is N(Ar), N(R), P(Ar), P(R), O, S or Se, or that Z.sup.1 is selected from B, Al, P(═O), P(═S) and Ga, and the Z.sup.2, Y.sup.3 group is N or P, or that Z.sup.2 is selected from B, Al, P(═O), P(═S) and Ga, and at least one of the Y.sup.2, Y.sup.3 groups is N(Ar), N(R), P(Ar), P(R), O, S or Se.

26. A compound as claimed in claim 20, that Z.sup.1 and/or Z.sup.2 is/are B.

27. A compound as claimed in claim 20, that Z.sup.1 and/or Z.sup.2 is/are N.

28. A compound as claimed in claim 20, wherein at least two R radicals form a fused ring together with the further groups to which the two R radicals bind, where the two R radicals form at least one structure of the formulae (RA-1) to (RA-12): where R.sup.1 has the definition set out above, the dotted bonds represent the sites of attachment to the atoms of the groups to which the two R radicals bind, and the further symbols have the following definition: ##STR00335## ##STR00336## Y.sup.4 is the same or different at each instance and is C(R.sup.1).sub.2, (R.sup.1).sub.2C—C(R.sup.1).sub.2, (R.sup.1)C═C(R.sup.1), NR.sup.1, NAr, O or S; R.sup.a is the same or different at each instance and is F, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or an alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 carbon atoms, where the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group may be substituted in each case by one or more R.sup.2 radicals, where one or more non-adjacent CH.sub.2 groups may be replaced by R.sup.2C═CR.sup.2, —C≡C—, Si(R.sup.2).sub.2, C═O, C═S, C═Se, C═NR.sup.2, —C(═O)O—, —C(═O)NR.sup.2—, NR.sup.2, P(═O)(R.sup.1), —O—, —S—, SO or SO.sub.2, or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and may be substituted in each case by one or more R.sup.2 radicals, or an aryloxy or heteroaryloxy group which has 5 to 60 aromatic ring atoms and may be substituted by one or more R.sup.2 radicals; or two R.sup.a radicals together may form a ring system; s is 0, 1, 2, 3, 4, 5 or 6; t is 0, 1, 2, 3, 4, 5, 6, 7 or 8; v is 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9.

29. A compound as claimed in claim 20, that at least two R radicals form a fused ring together with the further groups to which the two R radicals bind, where the two R radicals form of the structures of the formulae (RA-1a) to (RA-4f): ##STR00337## ##STR00338## where the index m is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, and the symbols R1, R2, Ra and the indices s and t have the definition set out above, especially in claim 20.

30. A compound as claimed in claim 20, that at least two R radicals form a fused ring together with the further groups to which the two R radicals bind, where the two R radicals form of the structures of the formula (RB): ##STR00339## where R.sup.1 has the definition set out in claim 20, the index m is 0, 1, 2, 3 or 4, and Y.sup.5 is C(R.sup.1).sub.2, NR.sup.1, NAr, BR.sup.1, BAr, O or S.

31. A compound as claimed in claim 20, comprising at least one structure of the formulae (IVa) to (IVr), where the compounds have at least one fused ring: ##STR00340## ##STR00341## ##STR00342## ##STR00343## ##STR00344## where Y.sup.2, Y.sup.3, X, Z.sup.1, Z.sup.2 and R have the definitions given in claim 20, the symbol o represents the sites of attachment, the index 1 is 0, 1, 2, 3, 4 or 5, the index m is 0, 1, 2, 3 or 4, the index n is 0, 1, 2 or 3, the index j is 0, 1 or 2, and the index k is 0 or 1, where the sum total of the indices k, j, 1, m and n is 0, 1, 2, 3, 4, 5 or 6.

32. A compound as claimed in claim 28, wherein the compounds have at least two fused rings, wherein at least one fused ring is formed by structures of the formulae (RA-1) to (RA-12) and a further ring is formed by structures of the formulae (RA-1) to (RA-12) or (RB), comprising at least one structure of the formulae (Va) to (Vs): ##STR00345## ##STR00346## ##STR00347## ##STR00348## ##STR00349## ##STR00350## where Y.sup.2, Y.sup.3, X, Z.sup.1, Z.sup.2 and R have the definitions given in claim 20, the symbol o represents the sites of attachment of at least one structure of the formulae (RA-1) to (RA-12) or a structure of the formula (RB), the index l is 0, 1, 2, 3, 4 or 5, the index m is 0, 1, 2, 3 or 4, the index n is 0, 1, 2 or 3, the index j is 0, 1 or 2, and the index k is 0 or 1, where the sum total of the indices k, j, l, m and n is 0, 1, 2, 3 or 4.

33. An oligomer, polymer or dendrimer containing one or more compounds as claimed in claim 20, wherein, rather than a hydrogen atom or a substituent, there are one or more bonds of the compounds to the polymer, oligomer or dendrimer.

34. A formulation comprising at least one compound as claimed in claim 20 and at least one further compound, where the further compound is preferably selected from one or more solvents.

35. A composition comprising at least one compound as claimed in claim 20 and at least one further compound selected from the group consisting of fluorescent emitters, phosphorescent emitters, emitters that exhibit TADF, host materials, electron transport materials, electron injection materials, hole conductor materials, hole injection materials, electron blocker materials and hole blocker materials.

36. A process for preparing a compound as claimed in claim 20, wherein a base skeleton having a Z.sup.1 group or a precursor of the Z.sup.1 group is synthesized, and then a ring closure reaction is conducted by means of a nucleophilic aromatic substitution reaction or a coupling reaction.

37. A method comprising incorporating the compound as claimed in claim 20 in an electronic device.

38. An electronic device comprising at least one compound as claimed in claim 20, wherein the electronic device is preferably an electroluminescent device.

Description

EXAMPLES

[0148] The syntheses which follow, unless stated otherwise, are conducted under a protective gas atmosphere in dried solvents. The metal complexes are additionally handled with exclusion of light or under yellow light. The solvents and reagents can be purchased, for example, from Sigma-ALDRICH or ABCR. The respective figures in square brackets or the numbers quoted for individual compounds relate to the CAS numbers of the compounds known from the literature. In the case of compounds that can have multiple enantiomeric, diastereomeric or tautomeric forms, one form is shown in a representative manner.

Synthesis of Synthons S

Example S1

[0149] ##STR00204##

[0150] To a well-stirred mixture of 33.3 g (100 mmol) of 1-bromo-2-iodonaphthalene [90948-03-1], 4.6 g (50 mmol) of aniline [62-53-3], 24.2 g (250 mmol) of sodium tert-butoxide in 600 ml of toluene are added 405 mg (2 mmol) of tri-tert-butylphosphine [131274-22-2] and then 404 mg (1.8 mmol) of palladium(II) acetate, and the mixture is then stirred at 70° C. for 16 h. After cooling, the reaction mixture is washed three times with 500 ml each time of water and once with 500 ml of saturated sodium chloride solution. The organic phase is dried over magnesium sulfate, the magnesium sulfate is filtered therefrom through a silica gel bed in the form of a toluene slurry, and the filtrate is concentrated under reduced pressure to dryness. The residue is subjected to flash chromatography, silica gel, n-heptane/ethyl acetate, Torrent automated column system from A. Semrau. Yield: 14.4 g (28.5 mmol) 57%; purity about 95% by .sup.1H NMR.

[0151] The following compounds can be prepared analogously:

TABLE-US-00003 Ex. Reactants Product Yield S2 [00205] [00206] [00207] 49% S3 [00208] [00209] [00210] 60% S4 [00211] [00212] [00213] 57% S5 [00214] [00215] [00216] 41% S6 [00217] [00218] [00219] 54% S50 [00220] [00221] 38% [00222] S51 [00223] [00224] [00225] 33% S52 [00226] [00227] [00228] 40% S53 [00229] [00230] [00231] 37% S54 [00232] [00233] [00234] 43% S55 [00235] [00236] [00237] 40% S56 [00238] [00239] [00240] 30%

Synthesis of the Compounds of the Invention

Example D1

[0152] ##STR00241##

[0153] A well-stirred mixture of 29.5 g (100 mmol) of dibenzo[c,h]acridin-7(14H)-one [50405-28-2], 30.0 g (110 mmol) of 2-iodo-1,3-dichlorobenzene [19230-28-5], 41.5 g (300 mmol) of potassium carbonate, anhydrous, 42.6 g (300 mmol) of sodium sulfate, anhydrous, 21.0 g (330 mmol) of copper powder, 100 g of glass beads (diameter 3 mm) and 300 ml of nitrobenzene is boiled at reflux for 24 h. After cooling, a mixture of 1000 ml of methanol and 500 ml of water is added, the mixture is stirred for a further 1 h, and the solids are filtered off with suction, washed five times with 100 ml each time of methanol and dried under reduced pressure. The residue is taken up in 500 ml of o-dichlorobenzene, boiled under reflux for 30 min, and then filtered with suction while still hot through a Celite bed in the form of a o-dichlorobenzene slurry. The filtrate is concentrated to a volume of about 50 ml at 80° C. under reduced pressure, and 100 ml of ethanol is added while it is still hot, which crystallizes the product. After cooling, the crystals are filtered off with suction, washed three times with 50 ml each time of ethanol and dried under reduced pressure. Purification is effected by repeated hot extraction crystallization with dichloromethane (DCM) (alternative solvents: toluene, benzonitrile, chlorobenzene, dimethylacetamide, etc.) and final fractional sublimation or heat treatment under high vacuum. Yield: 13.3 g (36 mmol), 36%; purity: >99.5% by .sup.1H NMR/HPLC.

[0154] The following compounds can be prepared analogously:

TABLE-US-00004 Ex. Reactants Product Yield D2 [00242] [00243] [00244] 33% D3 50405-28-2 [00245] [00246] 29% D4 50405-28-2 [00247] [00248] 41% D5 [00249] [00250] 23% D6 [00251] [00252] 56% D7 [00253] [00254] 53% D8 [00255] [00256] 47% D9 [00257] [00258] 48% D10 [00259] [00260] 40% D11 [00261] [00262] 37%

Example D50

[0155] Steps 1-3 of the sequence that follows are conducted as a one-pot reaction.

##STR00263##

[0156] Step 1: Lithiation of S1

##STR00264##

[0157] Intermediate, not Isolated

[0158] A baked-out, argon-inertized four-neck flask with magnetic stirrer bar, dropping funnel, water separator, reflux condenser and argon blanketing is charged with 28.0 g (50 mmol) of S1 in 1500 ml of tert-butylbenzene. The reaction mixture is cooled down to −45° C., and then 110.5 ml (210 mmol) of tert-butyllithium, 1.9 M in n-pentane, is added dropwise for 30 min. The mixture is stirred at −40° C. for a further 30 min, allowed to warm up to room temperature, then heated 70° C., in the course of which the n-pentane is distilled off via the water separator over about 1 h.

[0159] Step 2: Transmetalation and Cyclization

##STR00265##

[0160] Intermediate, not Isolated

[0161] The reaction mixture is cooled back down to −40° C. 5.2 ml (55 mmol) of boron tribromide is added dropwise over a period of about 10 min. On completion of addition, the reaction mixture is stirred at RT for 1 h and then cooled back down to −40° C.

[0162] Step 3: Arylation

##STR00266##

[0163] Intermediate, not Isolated

[0164] A second baked-out, argon-inertized Schlenk flask with magnetic stirrer bar is charged with 8.8 g (60 mmol) of 1,3-dichlorobenzene [541-73-1] in 300 ml of THF and cooled down to −78° C. Then 24.0 ml (60 mmol) of n-butyllithium, 2.5 M in n-hexane, is added dropwise thereto for about 20 min; the mixture is then stirred for a further 1.5 h. The reaction mixture is allowed to warm up to RT and stirred for a further 1 h, and the solvent is removed completely under reduced pressure. The lithium organyl is suspended in 300 ml of toluene and transferred into the cold reaction mixture from step 2. The mixture is stirred for a further 1 h, and the reaction mixture is left to warm up to RT overnight. 50 ml of methanol is added cautiously to the reaction mixture, and then the solvent is removed completely under reduced pressure.

[0165] Step 4: Cyclization

[0166] The solids from step 3 are taken up in 300 ml of dimethylacetamide (DMAC), 27.6 g (200 mmol) of potassium carbonate, 50 g of glass beads (diameter 3 mm) and 1.72 g (3 mmol) of (NHC)Pd(Allyl)Cl[478980-03-9] are added, and the well-stirred reaction mixture is heated to 130° C. for 18 h. The still-hot reaction mixture is filtered through a Celite bed in the form of a hot DMAC slurry, the filtrate is largely concentrated under reduced pressure, 300 ml of hot ethanol is added, and the mixture is stirred for a further 1 h. The product is filtered off with suction while the mixture is still hot, washed three times with 50 ml each time of ethanol and dried under reduced pressure. Purification is effected by repeated hot extraction crystallization with dichloromethane (DCM) (alternative solvents: toluene, benzonitrile, chlorobenzene, dimethylacetamide, etc.) and final fractional sublimation or heat treatment under high vacuum. Yield: 9.4 g (22 mmol), 44%; purity: >99.5% by .sup.1H NMR/HPLC.

[0167] The following compounds can be prepared analogously:

TABLE-US-00005 Ex. Reactants Product Yield D51 [00267] [00268] 23% D52 [00269] [00270] 39% D53 [00271] [00272] 35% D54 [00273] [00274] 19% D55 [00275] [00276] 19% D56 [00277] [00278] [00279] D57 [00280] [00281] [00282] 44% D58 [00283] [00284] [00285] 21% D59 [00286] [00287] [00288] 37% D60 [00289] [00290] [00291] 39% D61 [00292] [00293] [00294] 40% D62 [00295] [00296] [00297] 11% D63 [00298] [00299] [00300] 27% D64 [00301] [00302] [00303] 35% D100 [00304] [00305] [00306] 31% D101 [00307] [00308] [00309] 18% D102 [00310] [00311] [00312] 34% D103 [00313] [00314] [00315] 28% D104 [00316] [00317] [00318] 37% D105 [00319] [00320] [00321] 25% D106 [00322] [00323] [00324] 19%

[0168] 1) Vacuum-Processed Devices:

[0169] OLEDs of the invention and OLEDs according to the prior art are produced by a general method according to WO 2004/058911, which is adapted to the circumstances described here (variation in layer thickness, materials used).

[0170] In the examples which follow, the results for various OLEDs are presented. Cleaned glass plates (cleaning in Miele laboratory glass washer, Merck Extran detergent) coated with structured ITO (indium tin oxide) of thickness 50 nm are pretreated with UV ozone for 25 minutes (PR-100 UV ozone generator from UVP) and, within 30 min, for improved processing, coated with 20 nm of PEDOT:PSS (poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), purchased as CLEVIOS™ P VP Al 4083 from Heraeus Precious Metals GmbH Deutschland, spun on from aqueous solution) and then baked at 180° C. for 10 min. These coated glass plates form the substrates to which the OLEDs are applied.

[0171] The OLEDs basically have the following layer structure: substrate/hole injection layer 1 (HIL1) consisting of Ref-HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm/hole transport layer 1 (HTL1) composed of 160 nm of HTM1/optional hole transport layer 2 (HTL2) 10 nm/emission layer (EML) 20 nm/hole blocker layer (HBL) 10 nm/electron transport layer (ETL) 20 nm/electron injection layer (EIL) composed of 1 nm of ETM2/and finally a cathode. The cathode is formed by an aluminum layer of thickness 100 nm.

[0172] First of all, vacuum-processed OLEDs are described. For this purpose, all the materials are applied by thermal vapor 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 SMB1:D1 (95:5%) mean here that the material SMB1 is present in the layer in a proportion by volume of 95% and D1 in a proportion of 5%. Analogously, the electron transport layer may also consist of a mixture of two materials. The exact structure of the OLEDs can be found in table 1. The materials used for production of the OLEDs are shown in table 3.

[0173] The OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectra, the current efficiency (measured in cd/A), the power efficiency (measured in Im/VV) and the external quantum efficiency (EQE, measured in percent) are, as a function of luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming Lambertian radiation characteristics. Electroluminescence spectra are determined at a luminance of 1000 cd/m.sup.2, and these are used to calculate the CIE 1931 y color coordinates.

[0174] Use of compounds of the invention as materials in OLEDs One use of the compounds of the invention is as hole transport material and dopant in the emission layer in OLEDs. The compounds D-Ref.1 according to table 3 are used as a comparison according to the prior art. The results for the OLEDs are collated in table 2.

TABLE-US-00006 TABLE 1 Structure of the OLEDs Ex. HTL2 EML HBL ETL Ref. 1 — SMB1:D-Ref. 1 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD5 D11 SMB1:D5 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD50 — SMB1:D50 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD51 — SMB1:D51 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD52 — SMB2:D52 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD54 D6 SMB1:D54 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD55 — SMB1:D55 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD57 D8 SMB1:D57 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD59 — SMB1:D59 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD60 — SMB3:D60 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD61 — SMB1:D61 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD62 — SMB1:D62 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD63 — SMB1:D63 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD100 — SMB1:D100 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD101 — SMB1:D101 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD102 — SMB1:D102 ETM1 ETM1:ETM2 (95%:5%) (50%:50%) DD105 D10 SMB1:D105 ETM1 ETM1:ETM2 (95%:5%) (50%:50%)

TABLE-US-00007 TABLE 2 Results for the vacuum-processed OLEDs EQE (%) Voltage (V) Lmax. EL-FWHM Ex. 1000 cd/m.sup.2 1000 cd/m.sup.2 [nm] [nm] Ref. 1 2.9 5.6 506 53 DD5 5.4 4.5 490 34 DD50 6.0 4.3 433 27 DD51 5.8 4.3 403 26 DD52 5.7 4.3 439 29 DD54 5.5 4.2 436 28 DD55 5.8 4.4 438 30 DD57 8.2 4.3 435 29 DD59 7.3 4.4 448 31 DD60 7.0 4.2 452 33 DD61 8.5 4.4 483 51 DD62 5.6 4.2 433 31 DD63 6.3 4.4 478 35 DD100 7.3 4.2 465 26 DD101 7.7 4.2 473 29 DD102 8.5 4.3 468 28 DD105 8.0 4.5 460 30

TABLE-US-00008 TABLE 3 Structural formulae of the materials used [00325] HTM1 [00326] SMB1 [00327] SMB2 [00328] SMB3 [00329] Ref.-D1 [00330] ETM1 [00331] ETM2

[0175] The compounds of the invention, by comparison with the references, show bluer emission, identifiable by the shorter emission wavelength ELmax., combined with narrower electroluminescence spectra, identifiable by the smaller EL-FWHM values (ELectroluminescence-Full Width Half Maximum—width of the EL emission spectra in nm at half the peak height), which leads to distinctly improved color purity (smaller CIE y values). Moreover, EQE values (External Quantum Efficiencies) are distinctly greater and operating voltages are distinctly lower compared to the reference, which leads to a distinct improvement in power efficiencies of the device and hence to lower power consumption.