Materials for organic electroluminescent devices

A compound of formula (1)

• wherein
• Ar is, identically or differently on each occurrence, phenyl, 1-naphthyl, 2-naphthyl, 2-anthryl, 9-anthryl, 2-phenanthrenyl, 3-phenanthrenyl or 9-phenanthrenyl each optionally substituted by one or more radicals R′;
• R is, identically on each occurrence, F, Si(R2)3;
• —N(Ar1)2;
• a straight-chain alkyl or alkoxy group having 1 to 4 C atoms or a branched alkyl group having 3 to 5 C atoms, each of which may be substituted by one or more radicals R2, where one or more H atoms may be replaced by F, or a phenyl group;
• R1
• are, identically or differently on each occurrence, F;
• Cl;
• Br;
• I;
• CN;
• N(Ar1)2;
• C(═O)Ar1;
• P(Ar1)2;
• P(═O)(Ar1)2;
• Si(R2)3;
• NO2;
• a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms optionally substituted by one or more radicals R2;
• or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 C atoms optionally substituted by one or more radicals R2;
• wherein one or more non-adjacent CH2 groups of said straight-chain alkyl, alkoxy or thioalkoxy group or said branched or cyclic alkyl, alkoxy or thioalkoxy group are optionally replaced by —R2C═CR2—, —C≡C—, Si(R2)2, Ge(R2)2, Sn(R2)2, C═O, C═S, C═Se, C═NR2, —O—, —S—, —N(R2)—, or —CONR2— and wherein one or more H atoms of said straight-chain alkyl, alkoxy or thioalkoxy group or said branched or cyclic alkyl, alkoxy or thioalkoxy group are optionally replaced by F, Cl, Br, I, CN, or NO2;
• an aromatic or hetero-aromatic ring system having 5 to 30 aromatic ring atoms optionally substituted by one or more radicals R2;
• or an aryloxy or heteroaryloxy group having 5 to 24 aromatic ring atoms optionally substituted by one or more radicals R2;
• or a combination of two, three, four or five substituents R1;
• Ar1 is, identically or differently on each occurrence, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms optionally substituted by one or more non-aromatic radicals R1 and wherein two radicals Ar1 are optionally connected to one another by a single bond or an O, S, N(R2), or C(R2)2 group;
• R2 is, identically or differently on each occurrence, H or a hydrocarbon radical having 1 to 20 C atoms, wherein said hydrocarbon radical is aliphatic, aromatic, or a combination of aliphatic and aromatic and is optionally substituted by F and wherein two or more radicals R2 optionally define a mono- or polycyclic, aliphatic or aromatic ring system with one another;
• n is 0;
• p is 0;
• with the proviso that if R1 contains a benzimidazole group, it is not bonded to Ar.