Neutral compound of the formula VII or VIII where the nitrogen heterocycles or the groups coordinated via N are defined as follows: where * denotes the atom which enters the complex bonding and # denotes the atom which is bonded to the second unit directly or via B", and the following applies to the other symbols used: Z 2 - Z 9 are on each occurrence, identically or differently, N or CR; R is selected on each occurrence, identically or differently, from the group consisting of H, D, F, Cl, Br, I, CN, NO 2, N(R 1) 2, C(=O)R 1, Si(R 1) 3, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms, each of which may be substituted by one or more radicals R 1, where one or more non-adjacent CH 2 groups may be replaced by R 1 C=CR 1, C≡C, Si(R 1) 2, Ge(R 1) 2, Sn(R 1) 2, C=O, C=S, C=Se, C=NR 1, P(=O)(R 1), SO, SO 2, NR 1, O, S or CONR 1 and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO 2, 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 1, an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R 1, or a combination of these systems, where two or more adjacent substituents R may optionally form a monocyclic or polycyclic, aliphatic, aromatic or heteroaromatic ring system, which may be substituted by one or more radicals R 1; R 1 is selected on each occurrence, identically or differently, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, in which one or more H atoms may be replaced by D, F, Cl, Br, I or CN, where two or more adjacent substituents R 3 may form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system with one another; Y is on each occurrence, identically or differently, O, S or NR; B" is a neutral bridge, in particular is on each occurrence, identically or differently, a divalent bridge, selected from NR, BR, O, CR 2, SiR 2, C=NR, C=CR 2, S, S=O, SO 2, PR and P(=O)R, L is a monodentate phosphine or arsine ligand R 3 E (where E = P or As); L- B"' -L is a phosphanyl or arsanyl radical (R 2 E#, where E = P or As), which is bonded to a further radical L via a bridge B'" and thus forms a bidentate ligand; B'" is the singly negatively charged bridge R 2 B(CH 2) 2. Z 2 - Z 9 are on each occurrence, identically or differently, N or CR; R is selected on each occurrence, identically or differently, from the group consisting of H, D, F, Cl, Br, I, CN, NO 2, N(R 1) 2, C(=O)R 1, Si(R 1) 3, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms, each of which may be substituted by one or more radicals R 1, where one or more non-adjacent CH 2 groups may be replaced by R 1 C=CR 1, C≡C, Si(R 1) 2, Ge(R 1) 2, Sn(R 1) 2, C=O, C=S, C=Se, C=NR 1, P(=O)(R 1), SO, SO 2, NR 1, O, S or CONR 1 and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO 2, 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 1, an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R 1, or a combination of these systems, where two or more adjacent substituents R may optionally form a monocyclic or polycyclic, aliphatic, aromatic or heteroaromatic ring system, which may be substituted by one or more radicals R 1; R 1 is selected on each occurrence, identically or differently, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, in which one or more H atoms may be replaced by D, F, Cl, Br, I or CN, where two or more adjacent substituents R 3 may form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system with one another; Y is on each occurrence, identically or differently, O, S or NR; B" is a neutral bridge, in particular is on each occurrence, identically or differently, a divalent bridge, selected from NR, BR, O, CR 2, SiR 2, C=NR, C=CR 2, S, S=O, SO 2, PR and P(=O)R, L is a monodentate phosphine or arsine ligand R 3 E (where E = P or As); L- B"' -L is a phosphanyl or arsanyl radical (R 2 E#, where E = P or As), which is bonded to a further radical L via a bridge B'" and thus forms a bidentate ligand; B'" is the singly negatively charged bridge R 2 B(CH 2) 2.