Materials for organic electroluminescent devices

A compound of formula (1),

• where the following applies to the symbols and indices used:
• Z stands, on each occurrence, identically or differently, for C═O, C═S, C═NR, BR, SO or SO2;
• E1 stands for N, B, P or P═O;
• E2, E3 stand, on each occurrence, identically or differently, for a single bond or for a divalent bridge selected from B(R0), N(RN), C(R0)2, Si(R0)2, C═O, C═NRN, C═C(R0)2, O, S, S═O, SO2, P(R0) or P(═O)R0;
• or a group E2 forms a lactam ring (L-1) as depicted below with one group X2, or a group E3 forms a lactam ring (L-1) with one group X3;
• where the sign “v” indicates the position of the group X2 or X3, which stands for C in this case, and the N atom marked with the sign “*” corresponds to E2 or E3;
• X stands, on each occurrence, identically or differently, for CR1 or N;
• X2, X3 stand, on each occurrence, identically or differently, for X;
• R0, R1, 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 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 having 5 to 60 aromatic ring atoms, which may be substituted by one or more R radicals, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R;
• where two radicals R0, R1, RN 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 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 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 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;
• m, n are, identically or differently, 0 or 1;
• with the proviso that m+n=1 or 2, and when m is 0, then E2 is absent and a group X is present at each bonding site of E2, and when n is 0, then E3 is absent and a group X is present at each bonding site of E3;
• and
• wherein at least one of the following is true:
• (i) E1 is P or P═O;
• (ii) Z is C═O, C═S, C═NR, SO, or SO2;
• (iii) at least one of E2 or E3 is C(R0)2, Si(R0)2, C═O, C═NRN C═C(R0)2, S═O, SO2, P(R0) or P(═O)R0;
• (iv) Z is BR and R is not joined to form an aliphatic, aromatic, or heteroaromatic ring system;
• or
• (v) E2 forms a lactam ring (L-1) with one group X2, or a group E3 forms a lactam ring (L-1) with one group X3.