Materials for organic electroluminescent devices

A compound of the formula (1),

• where the following applies to the symbols and indices used:
• V is on each occurrence, identically or differently, CR1 or N;
• or the two adjacent groups V stand for a group of formula (Z-1),
• where the dashed bonds in formula (Z-1) indicate the bonding to the structure of formula (1);
• and
• Z is on each occurrence, identically or differently, CR2 or N;
• W is CR2 or N;
• or two adjacent groups W stand for a group of formula (Z-1) as represented above;
• X1, X2 are on each occurrence, identically or differently, selected from the groups of formulae (X-1) to (X-9), with the proviso that X1 and X2 are not both a group of formula (X-1) in a compound of formula (1);
• where the dashed bonds in formulae (X-1) to (X-9) indicate the bonds to the 5-membered ring comprising X1 or X2;
• R1, R2 stand on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, N(R3)2, N(Ar)2, C(═O)Ar, P(═O)(Ar)2, S(═O)Ar, S(═O)2Ar, NO2, Si(R3)3, B(OR3)2, OSO2R3, a straight-chain alkyl, alkoxy or thioalkyl groups having 1 to 40 C atoms or branched or a cyclic alkyl, alkoxy or thioalkyl groups having 3 to 40 C atoms, each of which may be substituted by one or more radicals R3, where in each case one or more non-adjacent CH2 groups may be replaced by R3C═CR3, C≡C, Si(R3)2, Ge(R3)2, Sn(R3)2, C═O, C═S, C═Se, P(═O)(R3), SO, SO2, O, S or CONR3 and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO2, an aromatic or heteroaromatic ring systems having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R, or an aryloxy groups having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R3, where two adjacent substituents R1 and/or two adjacent substituents R2 may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R3;
• R3 stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, N(Ar)2, C(═O)Ar, P(═O)(Ar)2, S(═O)Ar, S(═O)2Ar, NO2, Si(R4)3, B(OR4)2, OS2R4, a straight-chain alkyl, alkoxy or thioalkyl groups having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 40 C atoms, each of which may be substituted by one or more radicals R4, where in each case one or more non-adjacent CH2 groups may be replaced by R4C═CR4, C≡C, Si(R4)2, Ge(R′)2, Sn(R4)2, C═O, C═S, C═Se, P(═O)(R4), SO, SO2, O, S or CONR4 and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO2, an aromatic or heteroaromatic ring systems having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R4, or an aryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R, where two adjacent substituents R3 may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R4;
• R4 stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CN, a straight-chain alkyl, alkoxy or thioalkyl groups having 1 to 20 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 20 C atoms, where in each case one or more non-adjacent CH2 groups may be replaced by SO, SO2, O, S and where one or more H atoms may be replaced by D, F, Cl, Br or I, or an aromatic or heteroaromatic ring system having 5 to 24 C atoms;
• Ar is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may in each case also be substituted by one or more radicals R4.