Compounds for electronic devices

Abstract

The present application relates to bridged triarylamines conforming to a defined formula. These compounds are suitable for use in electronic devices. The present application further relates to processes for preparing the compounds, and to electronic devices comprising the compounds.

Claims

1. A compound of formula (I) ##STR00260## where the variables that occur are as follows: Y is the same or different at each instance and is selected from a single bond, O and S, where there is at least one Y group selected from O and S; Z.sup.1 is the same or different at each instance and is CR.sup.1, N or C, where a Z.sup.1 group is C in the specific case when a Y group is bonded to it; Ar.sup.1 is the same or different at each instance and is an aromatic ring system which has 6 to 24 aromatic ring atoms and may be substituted by one or more R.sup.2 radicals; Cbz is a divalent group of the formula (Cbz) ##STR00261## substituted at each of its unoccupied positions by an R.sup.3 radical, where one of the two bonds of the divalent group to the rest of the compound is the dotted bond on the nitrogen atom of the formula (Cbz), where the second of these two bonds may be at any unoccupied position in the group, and where Z.sup.2 is the same or different at each instance and is selected from C and N; Ar.sup.2 is selected from the formulae ##STR00262## where the variables that occur are defined as follows: V is the same or different at each instance and is N or CR.sup.4, where at least one V group in each of formulae (Ar.sup.2-A), (Ar.sup.2-D) and (Ar.sup.2-E) is N; W is the same or different at each instance and is N or CR.sup.4; U is NR.sup.4; where at least one group selected from W and V groups in formula (Ar.sup.2—B) is N; and where one R.sup.4 group per formula is replaced by the bond to the Ar.sup.1 group or Cbz; R.sup.1, R.sup.2, R.sup.4 are the same or different at each instance and are selected from H, D, F, C(═O)R.sup.5, CN, Si(R.sup.5).sub.3, N(R.sup.5).sub.2, P(═O)(R.sup.5).sub.2, OR.sup.5, S(═O)R.sup.5, S(═O).sub.2R.sup.5, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where two or more R.sup.1 or R.sup.2 or R.sup.3 or R.sup.4 radicals may be joined to one another and may form a ring; where the alkyl, alkoxy, alkenyl and alkynyl groups mentioned and the aromatic ring systems and heteroaromatic ring systems mentioned may each be substituted by one or more R.sup.5 radicals; and where one or more CH.sub.2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups mentioned may be replaced by —R.sup.5C═CR.sup.5—, —C≡C—, Si(R.sup.5).sub.2, C═O, C═NR.sup.5, —C(═O)O—, —C(═O)NR.sup.5—, NR.sup.5, P(═O)(R.sup.5), —O—, —S—, SO, SO.sub.2; R.sup.3 are the same or different at each instance and are selected from H, D, F, C(═O)R.sup.5, CN, Si(R.sup.5).sub.3, N(R.sup.5).sub.2, P(═O)(R.sup.5).sub.2, OR.sup.5, S(═O)R.sup.5, S(═O).sub.2R.sup.5, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, and aromatic ring systems having 6 to 40 aromatic ring atoms; where two or more or R.sup.3 or R.sup.4 radicals may be joined to one another and may form a ring; where the alkyl, alkoxy, alkenyl and alkynyl groups mentioned and the aromatic ring systems; and where one or more CH.sub.2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups mentioned may be replaced by —R.sup.5C═CR.sup.5—, —C≡C—, Si(R.sup.5).sub.2, C═O, C═NR.sup.5, —C(═O)O—, —C(═O)NR.sup.5—, NR, P(═O)(R.sup.5), —O—, —S—, SO, SO.sub.2; R.sup.5 is the same or different at each instance and is selected from H, D, F, C(═O)R.sup.6, CN, Si(R.sup.6).sub.3, N(R.sup.6).sub.2, P(═O)(R.sup.6).sub.2, S(═OR.sup.6, S(═O)R.sup.6, S(═O).sub.2R.sup.6, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where two or more R.sup.5 radicals may be joined to one another and may form a ring; where the alkyl, alkoxy, alkenyl and alkynyl groups mentioned and the aromatic ring systems and heteroaromatic ring systems mentioned may each be substituted by one or more R.sup.6 radicals; and where one or more CH.sub.2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups mentioned may be replaced by —R.sup.6C═CR.sup.6—, —C≡C—, Si(R.sup.6).sub.2, C═O, C═NR.sup.6, —C(═O)O—, —C(═O)NR.sup.6—, NR.sup.6, P(═O)(R.sup.6), —O—, —S—, SO, or SO.sub.2; R.sup.6 is the same or different at each instance and is selected from H, D, F, CN, alkyl or alkoxy groups having 1 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where two or more R.sup.6 radicals may be joined to one another and may form a ring; and where the alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems mentioned may be substituted by F or CN; i is the same or different at each instance and is 0 or 1, where at least two indices i in formula (I) are 1, and where the Y group in question is absent when the corresponding index i=0; n is 0, 1, 2, 3 or 4; and m is 0, 1, 2, 3 or 4.

2. The compound as claimed in claim 1, wherein the Cbz group is the same or different at each instance and is selected from carbazole, azacarbazole, benzocarbazole, dibenzocarbazole, indenocarbazole, indolocarbazole, carbazole fused to benzofuran and carbazole fused to benzothiophene, where the groups mentioned may each be substituted by one or more R.sup.3 radicals.

3. The compound as claimed in claim 1, wherein the Cbz group is selected from the formulae ##STR00263## ##STR00264## ##STR00265## ##STR00266## ##STR00267## where: T is C(R.sup.3).sub.2, O, S or NR.sup.3; where the dotted bonds represent the bonds to the rest of the compound, and where the groups in the abovementioned formulae may each be substituted by an R.sup.3 radical at any position shown as unsubstituted.

4. The compound as claimed in claim 1, wherein Y is the same or different at each instance and is selected from O and S.

5. The compound as claimed in claim 1, wherein Z.sup.1 is CR.sup.1 or C, where a Z.sup.1 group is C when a Y group is bonded thereto.

6. The compound as claimed in claim 1, wherein Ar.sup.1 is the same or different at each instance and is a divalent group derived from the base skeletons of benzene, biphenyl, terphenyl, naphthalene, and fluorene, where the divalent group may be substituted by one or more R.sup.2 radicals.

7. The compound as claimed in claim 1, wherein R.sup.1, R.sup.2, and R.sup.4 are the same or different at each instance and are selected from H, D, F, CN, Si(R.sup.5).sub.3, N(R.sup.5).sub.2, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where the alkyl or alkoxy groups mentioned, the aromatic ring systems mentioned and the heteroaromatic ring systems mentioned may each be substituted by one or more R.sup.5 radicals; and where one or more CH.sub.2 groups in the alkyl or alkoxy groups mentioned may be replaced by —C≡C—, —R.sup.5═CR.sup.5—, Si(R.sup.5).sub.2, C═O, C═NR.sup.5, —NR.sup.5—, —O—, —S—, —C(═O)O— or —C(═O)NR.sup.5—.

8. The compound as claimed in claim 1, wherein R.sup.5 is the same or different at each instance and is selected from H, D, F, CN, Si(R.sup.6).sub.3, N(R.sup.6).sub.2, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where the alkyl and alkoxy groups mentioned, the aromatic ring systems mentioned and the heteroaromatic ring systems mentioned may each be substituted by one or more R.sup.6 radicals; and where one or more CH.sub.2 groups in the alkyl or alkoxy groups mentioned may be replaced by —C≡C—, —R.sup.6C═CR.sup.6—, Si(R.sup.6).sub.2, C═O, C═NR.sup.6, —NR.sup.6—, —O—, —S—, —C(═O)O— or —C(═O)NR.sup.6—.

9. The compound as claimed in claim 1, wherein R.sup.6 is H.

10. The compound as claimed in claim 1, wherein m and n at each instance are 0.

11. The compound as claimed in claim 1, wherein formula (I) conforms to one of the following formulae ##STR00268## ##STR00269## ##STR00270## ##STR00271## ##STR00272## where the variables that occur are as defined in claim 1, and the formulae may be substituted at each of the positions shown as unsubstituted on the aromatic six-membered rings by an R.sup.1 group.

12. A process for preparing a compound as claimed in claim 1, characterized in that, in a first step, a triphenylamine compound substituted by a reactive group on one of the phenyl groups is prepared, where the bridges between the phenyl groups are selected from single bond, O and S, and where at least 2 bridges are present, and in that, in a further step, a carbazole group is introduced into the compound via a transition metal-catalyzed coupling reaction.

13. An oligomer, polymer or dendrimer containing one or more compounds of formula (I) as claimed in claim 1, wherein the bond(s) to the polymer, oligomer or dendrimer may be localized at any desired positions substituted by R.sup.1, R.sup.2, R.sup.3 or R.sup.4 in formula (I).

14. A formulation comprising at least one compound as claimed in claim 1, and at least one solvent.

15. An electronic device comprising at least one compound as claimed in claim 1.

16. The electronic device as claimed in claim 15, wherein the device is an organic electroluminescent device comprising anode, cathode and at least one emitting layer, where it is at least one organic layer of the device, which is an emitting layer, an electron transport layer or a hole blocker layer, that comprises the at least one compound.

17. The compound as claimed in claim 1, wherein Ar.sup.e is selected from pyridine, pyrimidine, pyridazine, pyrazine, triazine, benzimidazole, quinoline, quinazoline, benzo[h]quinazoline, phenanthroline, phenanthridine, diazaphenanthrene, and acridine that may each be substituted by one or more R.sup.4 radicals.

18. A compound of formula (I) ##STR00273## where the variables that occur are as follows: Y is the same or different at each instance and is selected from a single bond, O and S, where there is at least one Y group selected from O and S; Z.sup.1 is the same or different at each instance and is CR.sup.1, N or C, where a Z.sup.1 group is C in the specific case when a Y group is bonded to it; Ar.sup.1 is the same or different at each instance and is an aromatic ring system which has 6 to 24 aromatic ring atoms and may be substituted by one or more R.sup.2 radicals; Cbz is a divalent group of the formula (Cbz) ##STR00274## substituted at each of its unoccupied positions by an R.sup.3 radical, where one of the two bonds of the divalent group to the rest of the compound is the dotted bond on the nitrogen atom of the formula (Cbz), where the second of these two bonds may be at any unoccupied position in the group, and where Z.sup.2 is the same or different at each instance and is selected from C and N; Ar.sup.2 is selected from triazine and quinazoline that may each be substituted by one or more R.sup.4 radicals; R.sup.1, R.sup.2, R.sup.4 are the same or different at each instance and are selected from H, D, F, C(═O)R.sup.5, CN, Si(R.sup.5).sub.3, N(R.sup.5).sub.2, P(═O)(R.sup.5).sub.2, OR.sup.5, S(═O)R.sup.5, S(═O).sub.2R.sup.5, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where two or more R.sup.1 or R.sup.2 or R.sup.3 or R.sup.4 radicals may be joined to one another and may form a ring; where the alkyl, alkoxy, alkenyl and alkynyl groups mentioned and the aromatic ring systems and heteroaromatic ring systems mentioned may each be substituted by one or more R.sup.5 radicals; and where one or more CH.sub.2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups mentioned may be replaced by —R.sup.5C═CR.sup.5—, —C≡C—, Si(R.sup.5).sub.2, C═O, C═NR.sup.5, —C(═O)O—, —C(═O)NR.sup.5—, NR.sup.5, P(═O)(R.sup.5), —O—, —S—, SO, SO.sub.2; R.sup.3 are the same or different at each instance and are selected from H, D, F, C(═O)R.sup.5, CN, Si(R.sup.5).sub.3, N(R.sup.5).sub.2, P(═O)(R.sup.5).sub.2, OR.sup.5, S(═O)R.sup.5, S(═O).sub.2R.sup.5, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, and aromatic ring systems having 6 to 40 aromatic ring atoms; where two or more or R.sup.3 or R.sup.4 radicals may be joined to one another and may form a ring; where the alkyl, alkoxy, alkenyl and alkynyl groups mentioned and the aromatic ring systems; and where one or more CH.sub.2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups mentioned may be replaced by —R.sup.5C═CR.sup.5—, —C≡C—, Si(R.sup.5).sub.2, C═O, C═NR.sup.5, —C(═O)O—, —C(═O)NR.sup.5—, NR.sup.5, P(═O)(R.sup.5), —O—, —S—, SO, SO.sub.2; R.sup.5 is the same or different at each instance and is selected from H, D, F, C(═O)R.sup.6, CN, Si(R.sup.6).sub.3, N(R.sup.6).sub.2, P(═O)(R.sup.6).sub.2, OR.sup.6, S(═O)R.sup.6, S(═O).sub.2R.sup.6, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where two or more R.sup.5 radicals may be joined to one another and may form a ring; where the alkyl, alkoxy, alkenyl and alkynyl groups mentioned and the aromatic ring systems and heteroaromatic ring systems mentioned may each be substituted by one or more R.sup.6 radicals; and where one or more CH.sub.2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups mentioned may be replaced by —R.sup.6C═CR.sup.6—, —C≡C—, Si(R.sup.6).sub.2, C═O, C═NR.sup.6, —C(═O)O—, —C(═O)NR.sup.6—, NR.sup.6, P(═O)(R.sup.6), —O—, —S—, SO, or SO.sub.2; R.sup.6 is the same or different at each instance and is selected from H, D, F, CN, alkyl or alkoxy groups having 1 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where two or more R.sup.6 radicals may be joined to one another and may form a ring; and where the alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems mentioned may be substituted by F or CN; is the same or different at each instance and is 0 or 1, where at least two indices i in formula (I) are 1, and where the Y group in question is absent when the corresponding index i=0; n is 0, 1, 2, 3 or 4; and m is 0, 1, 2, 3 or 4.

Description

WORKING EXAMPLES

A) Synthesis Examples

Stage a) 7-bromo[1,4]benzothiazino[2,3,4-kl]phenothiazine

(1) ##STR00072##

(2) To a solution of [1,4]benzothiazino[2,3,4-kl]phenothiazine (CAS 1050521-47, 48.5 g, 154 mmol) in chloroform (1000 ml) is added N-bromosuccinimide (24.7 g, 139 mmol) in portions at 0° C. with exclusion of light, and the mixture is stirred at this temperature for 2 h. The reaction is ended by addition of sodium sulfite solution and the mixture is stirred at room temperature for a further 30 min. After phase separation, the organic phase is washed with water and the aqueous phase is extracted with dichloromethane. The combined organic phases are dried over sodium sulfate and concentrated under reduced pressure. The residue is dissolved in ethyl acetate and filtered through silica gel. Subsequently, the crude product is recrystallized from heptane.

(3) Yield: 42 g (110 mmol), 64% of theory, colorless solid.

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

(5) TABLE-US-00002 No. Reactant Product Yield 2a 82% 3a 65% 4a 71%

(6) In an analogous manner, two eq. of NBS can be used to obtain the following compounds:

(7) TABLE-US-00003 No. Reactant Product Yield 5a 0 56% 6a 58% 7a 51%

Stage b) dithia-13b-azanaphtho[3,2,1-de]anthracene-7-boronic acid

(8) ##STR00085##

(9) 28 g (73 mmol) of 7-bromo-[1,4]benzothiazino[2,3,4-kl]phenothiazine are dissolved in 150 ml of dry THF and cooled to −78° C. At this temperature, 30 ml (76 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, 15 g (145 mmol) of trimethyl borate are added very rapidly and the reaction is allowed to come gradually to room temperature (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: 22 g (63 mmol), 90% of theory.

(10) The following compounds are prepared in an analogous manner:

(11) TABLE-US-00004 No. Reactant Product Yield 2b 69% 3b 71% 4b 0 72% 5b 68% 6b 66% 7b 68% 8b 71% 9b 00 01 80%

Stage c): 3,7-Bis(dibenzofuran-1-yl)-5,9-dioxa-13b-azanaphtho[3,2,1de]anthracene

(12) ##STR00102##

(13) To a degassed mixture of 116 g (470 mmol) of 1-bromodibenzofuran, 169 g (470.0 mmol) of 5,9-dioxa-13b-azanaphtho[3,2,1-de]anthracene-3,7-bisboronic acid, 149.02 g (702.0 mmol) of K.sub.3PO.sub.4, 1000 ml of dioxane and 1000 ml of water are added 13.52 g (11.7 mmol) of Pd(PPh.sub.3).sub.4. After heating the mixture to 80° C. for 7 h, 4.58 g (93.6 mmol) of NaCN are added. After cooling to room temperature, the aqueous phase is removed. The organic phase is washed twice with H.sub.2O and then dried over Na.sub.2SO.sub.4. After the solvent has been removed and the dark red solid has been recrystallized twice from dioxane, the product was obtained in the form of red needles.

(14) Yield: 184 g (304 mmol), 66% of theory; purity: 97% by HPLC.

(15) The following compounds can be prepared in an analogous manner:

(16) TABLE-US-00005 No. Reactant 1 Reactant 2 Product Yield 1c 03 04 05 80% 2c 06 07 08 74%

Stage d) 3-bromo-7,11-bis(dibenzofuran-1-yl)-5,9-dioxa-13b-azanaphtho[3,2,1-de]anthracene

(17) ##STR00109##

(18) 45.1 g (74.6 mmol) of 3,7-bis(dibenzofuran-1-yl)-5,9-dioxa-13b-azanaphtho[3,2,1de] anthracene are initially charged in 80 ml of DMF. Subsequently, 13.3 g (74.6 mmol) of NBS are added in portions and stirring is continued at this temperature for 4 h. Subsequently, 15 ml of water are added to the mixture and extraction is effected with CH.sub.2Cl.sub.2. The organic phase is dried over MgSO.sub.4 and the solvents are removed under reduced pressure. The product is subjected to extractive stirring with hot hexane and filtered off with suction. Yield: 39 g (58 mmol), 78% of theory, purity by .sup.1H NMR about 96%.

(19) The following compounds can be prepared in an analogous manner:

(20) TABLE-US-00006 No. Reactant 1 Product Yield 1d 0 80% 2d 74%

Stage e) 7-[9-(4,6-diphenyl-[1,3,5]triazin-2-yl)-9H-carbazol-3-yl]-5,9-dithia-13b-azanaphtho[3,2,1-de]anthracene

(21) ##STR00114##

(22) 11 g (32 mmol) of dithia-13b-azanaphtho[3,2,1-de]anthracene-7-boronic acid, 14 g (31.6 mmol) of 3-bromo-9-(4,6-diphenyl-[1,3,5]triazin-2-yl)-9H-carbazole, and 31 ml (63 mmol) of Na.sub.2CO.sub.3 (2 M solution) are suspended in 120 ml of toluene, 120 ml of ethanol. 0.73 g (0.63 mmol) of Pd(PPh.sub.3).sub.4 is added to this suspension, 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 purified by sublimation twice under reduced pressure (p=5×10.sup.−5 mbar, T=329° C.). The yield is 16.7 g (24 mmol), corresponding to 76% of theory.

(23) In an analogous manner, the following compounds are obtained:

(24) TABLE-US-00007 Ex. Reactant 1 Reactant 2 Product Yield  1e 64%  2e 0 63%  3e 73%  4e 79%  5e 70%  6e 0 74%  7e 71%  8e 65%  9e 0 87% 10e 73% 11e 72% 12e 0 70% 13e 77% 14e 76% 15e 70% 16e 0 69% 17e 80% 18e 72% 19e 0 73% 20e 77% 21e 71% 22e 0 56% 23e 72% 24e 78% 25e 77% 26e 0 70% 27e 67% 28e 69% 29e 00 01 72% 31e 02 03 04 67% 32e 05 06 07 77% 33e 08 09 0 75% 34e 70% 35e 65% 36e 67% 37e 0 77% 38e 69% 39e 62% 40e 0 61% 41e 66%

B) Device Examples

(25) Examples I1 to I12 which follow (see table 1) show the use of the compounds of the invention in OLEDs. Examples C1 to C4 (see table 1) are reference examples.

(26) 1) General Description of the Production and Analysis of the OLEDs:

(27) 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.

(28) 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) and finally a cathode. The cathode is formed by an aluminum layer of thickness 100 nm. The HIL used is a 5 nm-thick layer of the material HATCN. The HTL used is a 125 nm-thick layer of the material SpMA1. The EBL used is a 10 nm-thick layer of the material SpMA3. The further construction of OLEDs can be inferred from table 1. The materials used for production of the OLEDs are shown in Table 2.

(29) All 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 IC5:1C3:TEG2 (55%:35%:10%) mean here that the material IC5 is present in the layer in a proportion by volume of 55%, IC3 in a proportion of 35% and TEG2 in a proportion of 10%, based in each case on volume. Analogously, the electron transport layer may also consist of a mixture of two materials.

(30) The OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectra and the current-voltage-luminance characteristics (IUL characteristics) are measured. The electroluminescence spectra are determined at a luminance of 1000 cd/m.sup.2, and the CIE 1931 x and y color coordinates are calculated therefrom.

(31) 2) Comparison of the inventive compounds IV1-1V4 with prior art compounds PA1 to PA4

(32) The materials of the invention can be used in the emission layer in phosphorescent red OLEDs. Compared to the prior art (compounds PA1-4 from examples C1-C4 in table 1), with use of the molecules of the invention as matrix material in the emission layer, a reduction in the voltage at a luminance of 1000 cd/m.sup.2 by 10% in each case is found (direct comparison of example I1 with C1, I2 with C2, I3 with C3 and I4 with C4). This constitutes a significant improvement in the OLEDs.

(33) 3) Use of the compounds of the invention in the emitting layer, in the hole blocker layer and in the electron transport layer of OLEDs.

(34) The inventive compounds IV1 to IV9 and IV13 to IV15 are used in examples I1 to I12 as matrix material in the emission layer in combination with phosphorescent emitters. The color coordinates of the electroluminescence spectra of the OLEDs from these experiments are CIEx=0.67 and CIEy=0.33. The materials are thus suitable for use in the emission layer of red OLEDs.

(35) In addition, the materials of the invention can be used successfully in the electron transport layer (ETL) or the hole blocker layer (HBL). This is shown in experiments 113-115. Here too, the color coordinates of the spectrum of the OLEDs are CIEx=0.67 and CIEy=0.33.

(36) TABLE-US-00008 TABLE 1 Structure of the OLEDs EML HBL ETL Ex. thickness thickness thickness C1 PA1:TER5 — ST2:LiQ (95%:5%) 40 nm (50%:50%) 35 nm C2 PA2:TER5 — s.o. (95%:5%) 40 nm C3 PA3:TER5 — s.o. (95%:5%) 40 nm C4 PA4:TER5 — s.o. (95%:5%) 40 nm I1 IV1:TER5 — s.o. (95%:5%) 40 nm I2 IV2:TER5 — s.o. (95%:5%) 40 nm I3 IV3:TER5 — s.o. (95%:5%) 40 nm I4 IV4:TER5 — s.o. (95%:5%) 40 nm I5 IV5:PA1:TER5 — s.o. (85%:10%:5%) 40 nm I6 IV6:TER5 — s.o. (95%:5%) 40 nm I7 IV7:TER5 — s.o. (95%:5%) 40 nm I8 IV8:TER5 — s.o (95%:5%) 40 nm I9 IV9:TER5 — s.o. (95%:5%) 40 nm I10 IV13:TER5 — s.o. (95%:5%) 40 nm I11 IV14:TER5 — s.o. (95%:5%) 40 nm I12 IV15:TER5 — s.o. (95%:5%) 40 nm I13 IV1:TER5 — IV10:LiQ (95%:5%) 40 nm (50%:50%) 35 nm I14 s.o. IV11 5 nm ST2:LiQ (50%:50%) 30 nm I15 s.o. SV12 5 nm s.o.

(37) TABLE-US-00009 TABLE 2 Structural formulae of the materials for the OLEDs HATCN SpMA1 SpMA3 ST2 TER5 0 LiQ PA1 PA2 PA3 PA4 IV1 IV2 IV3 IV4 IV5 0 IV6 IV7 IV8 IV9 IV10 IV11 IV12 IV13 IV14 IV15

B) Device Examples

(38) Examples I1 to I12 which follow (see table 1) show the use of the compounds of the invention in OLEDs. Examples C1 to C4 (see table 1) are reference examples.

(39) 1) General Description of the Production and Analysis of the OLEDs:

(40) 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.

(41) 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) and finally a cathode. The cathode is formed by an aluminum layer of thickness 100 nm. The HIL used is a 5 nm-thick layer of the material HATCN. The HTL used is a 125 nm-thick layer of the material SpMA1. The EBL used is a 10 nm-thick layer of the material SpMA3. The