Compounds for electronic devices

1. A compound of the formula (Ia)

wherein

X 1 , X 2 and X 3 are on each occurrence a divalent group selected, identically or differently, from BR 1 , C(R 1 ) 2 , Si(R 1 ) 2 , C═NR 1 , C═C(R 1 ) 2 , NR 1 , O, S, S═O, S(═O) 2 , PR 1 or P(═O)R 1 ;

Z is on each occurrence selected, identically or differently, from CR 1 and N;

Ar 1 and Ar 2 are on each occurrence, identically or differently, an aryl group having 6 to 60 aromatic ring atoms or a heteroaryl group having 5 to 60 aromatic ring atoms, wherein said aryl or heteroaryl group is optionally substituted by one or more radicals R 2 ;

R 1 and R 2 are on each occurrence, identically or differently,

H, D, F, CN, Si(R 3 ) 3 , N(R 3 ) 2 or a straight-chainalkyl or alkoxy group having 1 to 20 C atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 C atoms, wherein said straight-chain alkyl or alkoxy group or said branched or cyclic alkyl or alkoxy group is optionally substituted by one or more radicals R 3 , where one or more CH 2 groups in said straight-chain alkyl or alkoxy group or the branched or cyclic alkyl or alkoxy group is optionally replaced by —C≡C—, —R 3 C═CR 3 —, Si(R 3 ) 2 , C═O, C═NR 3 , —NR 3 —, —O—, —S—, —COO— or —CONR 3 —, or an aryl or heteroaryl group having 5 to 20 aromatic ring atoms, which may is optionally substituted by one or more radicals R 3 , where two or more radicals R 1 or R 2 may be linked to one another and may form an aliphatic or aromatic ring system;

R 3 is on each occurrence, identically or differently, H, D, F, CI, Br, B(OR 4 ) 2 , CHO, C(O)R 4 , CR 4 ═C(R 4 ) 2 , CN, COOR 4 , CON(R 4 ) 2 , Si(R 4 ) 3 , N(R 4 ) 2 , NO 2 , P(═O)(R 4 ) 2 , OSO 2 R 4 , OH, S(═O)R 4 , S(═O) 2 R 4 , a straight-chainalkyl, 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 or an alkenyl or alkynyl group having 2 to 40 C atoms, wherein said straight-chainalkyl, alkoxy or thioalkyl group or said branched or cyclic alkyl, alkoxy or thioalkyl group is optionally substituted by one or more radicals R 4 , where one or more CH 2 groups in said straight-chainalkyl, alkoxy or thioalkyl group or said branched or cyclic alkyl, alkoxy or thioalkyl group is optionally replaced by —R 4 C═CR 4 —, —C≡C—, Si(R 4 ) 2 , Ge(R 4 ) 2 , Sn(R 4 ) 2 , C═O, C═S, C═Se, C═NR 4 , —COO—, —CONR 4 —, NR 4 , P(═O)(R 4 ), —O—, —S—, SO or SO 2 and where one or more H atoms is optionally replaced by D, F, CI, Br, I, CN or NO 2 , or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, said aromatic or heteroaromatic ring system is optionally substituted by one or more radicals R 4 , or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals R 4 where two or more radicals R 3 is optionally linked to one another and may form an aliphatic or aromatic ring system;

R 4 is, identically or differently on each occurrence, H, D, F or an aliphatic, aromatic and/or heteroaromatic organic radical having 1 to 20 C atoms, in which, in addition, one or more H atoms in said organic radical is optionally replaced by D or F; two or more identical or different substituents R 4 here is optionally linked to one another and form an aliphatic or aromatic ring system;

and with the proviso that all three groups X 1 , X 2 and X 3 do not simultaneously represent O, that all three groups X 1 , X 2 and X 3 do not simultaneously represent S, and that, if one or more of the groups X′, X 2 and X 3 represent a group of the formula NR 1 , Was a constituent of the group NR 1 is an aryl or heteroaryl group having 5 to 20 aromatic ring atoms, which may in each case be substituted by one or more radicals R 3 .

2. The compound according to claim 1 , wherein X 1 , X 2 and X 3 are on each occurrence, identically or differently, selected from C(R 1 ) 2 , NR 1 , O or S and with the proviso that all three groups X 1 , X 2 and X 3 do not simultaneously represent O, that all three groups X 1 , X 2 and X 3 do not simultaneously represent S and that, if one or more of the groups X 1 , X 2 and X 3 represent a group of the formula NR 1 , R 1 as a constituent of the group NR 1 is an aryl or heteroaryl group having 5 to 20 aromatic ring atoms, which may in each case be substituted by one or more radicals R 3 .

3. The compound according to claim 1 , wherein the groups Ar 1 and Ar 2 are selected on each occurrence, identically or differently, from the following groups:

where the groups is optionally fused to the remainder of the compound via any desired bond Z—Z, where these Z cannot be equal to N, Z is otherwise as defined in claim 1 , and furthermore

Y is selected on each occurrence, identically or differently, from C(R 2 ) 2 , C═O, NR 2 , O, S, S═O or S(═O) 2 .

4. The compound according to claim 3 , wherein not more than three groups Z per aromatic ring are equal to N and the remaining groups Z are equal to CR 1 .

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

6. An electronic device which comprises the compound according to claim 1 .

7. The electronic device according to claim 6 , wherein the device is an organic electroluminescent device (OLED).

8. The electronic device according to claim 6 , wherein the device is an organic integrated circuit (O-IC), an organic field-effect transistor (O-FET), an organic thin-film transistor (O-TFT), an organic light-emitting transistor (O-LET), an organic solar cell (O-SC), an organic optical detector, an organic photoreceptor, an organic field-quench device (O-FQD), a light-emitting electrochemical cell (LEC), an organic laser diode (O-laser) or an organic electroluminescent device (OLED).

9. An electronic device which comprises the compound according to claim 1 is employed as a hole-transport material in a hole-transport layer or a hole-injection layer or is employed as a matrix material in an emitting layer or is employed as dopant in an emitting layer.