Compound of formula,,,, or where the symbols and indices used are as follows: X is the same or different at each instance and is CR or N; L 1, L 2 is the same or different at each instance and is a bidentate sub-ligand; V 1 is a trivalent group that joins the central subligand(s), according to the choice of n, to one another and to L 1; V 2 is a bivalent group or a single bond that joins the central sub-ligand and L 2 to one another; n is 1, 2 or 3; m is the same or different at each instance and is 0 or 1, where, when m = 1, the atom X to which the corresponding V 2 group is bonded is C, with the proviso that at least one m = 1; R is the same or different at each instance and is H, D, F, Cl, Br, I, N(R 1) 2, CN, NO 2, OR 1, SR 1, COOR 1, C(=O)N(R 1) 2, Si(R 1) 3, B(OR 1) 2, C(=O)R 1, P(=O)(R 1) 2, S(=O)R 1, S(=O) 2 R 1, OSO 2 R 1, a straightchain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R 1 radicals, where one or more nonadjacent CH 2 groups may be replaced by Si(R 1) 2, C=O, NR 1, O, S or CONR 1, or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted in each case by one or more R 1 radicals; at the same time, two R radicals together may also form a ring system; R 1 is the same or different at each instance and is H, D, F, Cl, Br, I, N(R 2) 2, CN, NO 2, OR 2, SR 2, Si(R 2) 3, B(OR 2) 2, COOR 2, C(=O)R 2, P(=O)(R 2) 2, S(=O)R 2, S(=O) 2 R 2, OSO 2 R 2, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R 2 radicals, where one or more nonadjacent CH 2 groups may be replaced by Si(R 2) 2, C=O, NR 2, O, S or CONR 2, or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted in each case by one or more R 2 radicals; at the same time, two or more R 1 radicals together may form a ring system; R 2 is the same or different at each instance and is H, D, F or an aliphatic, aromatic or heteroaromatic organic radical, especially a hydrocarbyl radical, having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F. X is the same or different at each instance and is CR or N; L 1, L 2 is the same or different at each instance and is a bidentate sub-ligand; V 1 is a trivalent group that joins the central subligand(s), according to the choice of n, to one another and to L 1; V 2 is a bivalent group or a single bond that joins the central sub-ligand and L 2 to one another; n is 1, 2 or 3; m is the same or different at each instance and is 0 or 1, where, when m = 1, the atom X to which the corresponding V 2 group is bonded is C, with the proviso that at least one m = 1; R is the same or different at each instance and is H, D, F, Cl, Br, I, N(R 1) 2, CN, NO 2, OR 1, SR 1, COOR 1, C(=O)N(R 1) 2, Si(R 1) 3, B(OR 1) 2, C(=O)R 1, P(=O)(R 1) 2, S(=O)R 1, S(=O) 2 R 1, OSO 2 R 1, a straightchain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R 1 radicals, where one or more nonadjacent CH 2 groups may be replaced by Si(R 1) 2, C=O, NR 1, O, S or CONR 1, or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted in each case by one or more R 1 radicals; at the same time, two R radicals together may also form a ring system; R 1 is the same or different at each instance and is H, D, F, Cl, Br, I, N(R 2) 2, CN, NO 2, OR 2, SR 2, Si(R 2) 3, B(OR 2) 2, COOR 2, C(=O)R 2, P(=O)(R 2) 2, S(=O)R 2, S(=O) 2 R 2, OSO 2 R 2, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R 2 radicals, where one or more nonadjacent CH 2 groups may be replaced by Si(R 2) 2, C=O, NR 2, O, S or CONR 2, or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted in each case by one or more R 2 radicals; at the same time, two or more R 1 radicals together may form a ring system; R 2 is the same or different at each instance and is H, D, F or an aliphatic, aromatic or heteroaromatic organic radical, especially a hydrocarbyl radical, having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F.