Materials for organic electroluminescent devices

Compound of the formula (1),

• where the following applies to the symbols and indices used:
• X stands on each occurrence, identically or differently, for CRX or N;
• Y1 stands for B(R0), Si(R0)2, C═O, C═NRN, C═C(R0)2, O, S, S═O, SO2, N(RN), P(R0) or P(═O)R0;
• Y2, Y3 and Y4 stand on each occurrence, identically or differently for B(R0), C(R0)2, Si(R0)2, C═O, C═NRN, C═C(R0)2, O, S, S═O, SO2, N(RN), P(R0) or P(═O)R0;
• RX, R0, RN stand on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, C(═O)Ar, P(═O)(Ar)2, S(═O)Ar, S(═O)2Ar, N(R)2, N(Ar)2, NO2, Si(R)3, B(OR)2, OSO2R, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or a cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R, where in each case one or more non-adjacent CH2 groups may be replaced by RC═CR, C≡C, Si(R)2, Ge(R)2, Sn(R)2, C═O, C═S, C═Se, P(═O)(R), SO, SO2, O, S or CONR and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO2, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R, an aralkyl or heteroaralkyl group which has 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R, or an aryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R;
• where two adjacent radicals RX may form an aliphatic, aromatic or heteroaromatic ring system together, which may be substituted by one or more radicals R;
• and where two adjacent radicals R0 may form an aliphatic, aromatic or heteroaromatic ring system together, which may be substituted by one or more radicals R;
• R stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, C(═O)Ar, P(═O)(Ar)2, S(═O)Ar, S(═O)2Ar, N(R′)2, N(Ar)2, NO2, Si(R′)3, B(OR′)2, OSO2R′, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or a cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R′, where in each case one or more non-adjacent CH2 groups may be replaced by R′C═CR′, C≡C, Si(R′)2, Ge(R′)2, Sn(R′)2, C═O, C═S, C═Se, P(═O)(R′), SO, SO2, O, S or CONR and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO2, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R′;
• where two adjacent substituents R may form an aliphatic or aromatic ring system together, which may be substituted by one or more radicals R′;
• 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 R′;
• R′ stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CN, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group 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 aromatic ring atoms;
• n, m, p are on each occurrence, identically or differently, 0 or 1, whereas when n, m or p is 0, then the corresponding group Y2, Y3 or Y4 is absent and the bonds to Y2, Y3 and Y4 are replaced by groups X, and wherein at least one of the index n, m or p is equal to 1.