METAL-COMPLEXES OF DYES .6. PHOSPHINE-NICKEL, PALLADIUM, PLATINUM COMPLEXES AND PENTAMETHYLCYCLOPENTADIENYL RHODIUM AND IRIDIUM COMPLEXES OF 2,2'-DIHYDROXYAZOARENES

The terdentate dianions of 2,2'-dihydroxyazobenzene (L(1)H), 1-(2-hydroxy-4-nitrophenylazo)-2-naphthol (L(2)H), 1-(2-hydroxy-5-nitrophenylazo)-2-naphthol (L(3)H) and 1-phenyl-3-methyl-4-(2-hydroxy-5-nitrophenylazo)-5-pyrazolone (L(4)H) form with chloro bridged complexes [(R(3)P)MCl(2)](2) (M = Pd, Pt; R = Ph, nBu), [(eta(5)-C(5)Me(5))MCl(2)](2) (M = Ph, Ir) and with (nBu(3)P)(2)NiCl2 the metal dye complexes (R(3)P)ML (M = Ni, Pd, Pt) and (C(5)Me(5))ML (M = Ph, Ir). The structures of (Ph(3)P)PtL(1) and (nBu(3)P)PdL(3) have been determined by X-ray diffraction. For the complexes (eta(5)-C(5)Me(5))ML (M = Rh, Ir) with asymmetric metal centers two diastereoisomers are detected by nmr spectroscopy which points to the ''hydrazone'' form of the azo ligand with a pyramidalized N-atom.