Rhodium and iridium complexes

A compound of the formula (I) or (II)

• where the symbols and indices are defined as follows:
• M is Rh or Ir;
• Y is O, S or Se;
• Z is B—R1, C(R)2, —CH═CH—, —CR1═CH—, —CR1═CR1—, C═O, NH, NR1, PR1, P(O)R1, P(S)R1, O, S, S═O, S(═O)2, Se or a C—C single bond;
• R is the same or different at each occurrence and is H, F, Cl, NO2, CN, a straight-chain or branched or cyclic alkyl or alkoxy group which has from 1 to 20 carbon atoms and in which one or more nonadjacent CH2 groups is optionally replaced by —O—, —S—, —NR1— or —CONR2—, and In which one or more hydrogen atoms is optionally replaced by F, or an aryl or heteroaryl group having from 4 to 14 carbon atoms which is optionally substituted by one or more nonaromatic R radicals;
• and a plurality of R substituents, either on the same ring or on the two different rings together form a further mono- or polycyclic ring system;
• Ar1 and Ar2 are the same or different and are each an aryl or heteroaryl group having from 1 to 40 carbon atoms;
• Q1 and Q2 are the same or different at each occurrence and are each F, Cl, Br, CN, NO2 or a straight-chain or branched or cyclic alkyl or alkoxy group which has from 1 to 20 carbon atoms and in which one or more nonadjacent CH2 groups is optionally replaced by —O—, —S—, —CO—, —COO—, —O—CO—, —NR1—, —(NR2R3)+A− or —CONR4, and in which one or more hydrogen atoms is optionally replaced by F, or an aryl or heteroaryl group having from 4 to 14 carbon atoms which is optionally substituted by one or more nonaromatic R radicals;
• A− is a singly charged anion;
• R1, R2, R3 and R4 are the same or different and are each H or an aliphatic or aromatic hydrocarbon radical having from 1 to 20 carbon atoms;
• a is 0, 1, 2, 3 or 4;
• b is 0, 1, 2 or 3;
• c and d are each 0, 1, 2, 3, 4 or 5;
• e is 0 or 1;
• n is 1, 2 or 3.