Compounds for electronic devices

A compound of a formula (I)

• where
• G is the same or different at each instance and is selected from a group of the formula (G-1)
• attached via the dotted bond,
• where, in formula (G-1), W is the same or different at each instance and is CR2 or N;
• or one or more units from any two adjacent W groups are the same or different at each instance and are selected from units of the formulae (W-1) to (W-2)
• where the dotted bonds represent the bonds to the rest of the formula (G-1);
• where U is the same or different at each instance and is selected from O, S, NR3 and C(R3)2;
• and
• where, in formula (W-1) to (W-2), V is the same or different at each instance and is CR2 or N;
• or one or more units from any two adjacent V groups are the same or different at each instance and are selected from units of the formulae (V-1) to (V-2)
• where the dotted bonds represent the bonds to the rest of the formulae (W-1) to (W-2);
• where Z is the same or different at each instance and is CR2 or N;
• X, when no G or T is bonded thereto, is the same or different at each instance and is N or CR1;
• and X, when G or T is bonded thereto, is C;
• T is a single bond that connects the X groups in question;
• R1 is the same or different at each instance and is selected from H, D, F, Cl, Br, I, C(═O)R4, CN, Si(R4)3, N(R4)2, P(═O)(R4)2, OR4, S(═O)R4, S(═O)2R4, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• where two or more R1 radicals may be joined to one another and may form a ring;
• where the alkyl, alkoxy, alkenyl and alkynyl groups and the aromatic ring systems and heteroaromatic ring systems are each substituted by R4 radicals;
• and where one or more CH2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups may be replaced by —R4C═CR4—, —C≡C—, Si(R4)2, C═O, C═NR4, —C(═O)O—, —C(═O)NR4—, NR4, P(═O)(R4), —O—, —S—, SO or SO2;
• R2 is the same or different at each instance and is selected from H, D, F, Cl, Br, I, C(═O)R4, CN, Si(R4)3, N(R4)2, P(═O)(R4)2, OR4, S(═O)R4, S(═O)2R4, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• where two or more R2 radicals may be joined to one another and may form a ring;
• where the alkyl, alkoxy, alkenyl and alkynyl groups and the aromatic ring systems and heteroaromatic ring systems are each substituted by R4 radicals;
• and where one or more CH2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups may be replaced by —R4C═CR4—, —C≡C—, Si(R4)2, C═O, C═NR4, —C(═O)O—, —C(═O)NR4—, NR4, P(═O)(R4), —O—, —S—, SO or SO2;
• R3 is the same or different at each instance and is selected from H, D, F, Cl, Br, I, CN, Si(R4)3, N(R4)2, straight-chain alkyl groups having 1 to 20 carbon atoms, branched or cyclic alkyl groups having 3 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• where two or more R3 radicals may be joined to one another and may form a ring;
• where the alkyl groups and the aromatic ring systems and heteroaromatic ring systems are each substituted by R4 radicals;
• R4 is the same or different at each instance and is selected from H, D, F, Cl, Br, I, C(═O)R5, CN, Si(R5)3, N(R5)2, P(═O)(R5)2, OR5, S(═O)R5, S(═O)2R5, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• where two or more R4 radicals may be joined to one another and may form a ring;
• where the alkyl, alkoxy, alkenyl and alkynyl groups and the aromatic ring systems and heteroaromatic ring systems are each substituted by R5 radicals;
• and where one or more CH2 groups in the alkyl, alkoxy, alkenyl and alkynyl groups may be replaced by —R5C═CR5—, —C≡C—, Si(R5)2, C═O, C═NR5, —C(═O)O—, —C(═O)NR5—, NR5, P(═O)(R5), —O—, —S—, SO or SO2;
• R5 is the same or different at each instance and is selected from H, D, F, Cl, Br, I, CN, alkyl or alkoxy groups having 1 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• where two or more R5 radicals may be joined to one another and may form a ring;
• and where the alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems may be substituted by one or more radicals selected from F and CN;
• k is 0 or 1, where, when k is 0, T is absent, and the X groups in question are not bonded to one another;
• m, n, o is the same or different at each instance and is selected from 0 and 1, where at least one of the indices m, n and o must be 1;
• where at least one X group in at least one of the rings to which a G group is bonded is N.