Bis[2-(phenylazo)phenyl-C 1 N′]gold( III ) complexes. Crystal and molecular structure of bis[2-(phenylazo)phenyl-C 1 N′]gold( III ) tetrachloroaurate

The reaction between [NMe4][AuCl4] and [Hg(pap)2][pap = 2-(phenylazo)phenyl] gave the gold(III) complex [Au(pap)2Cl] which reacts with AgClO4 to form [Au(pap)2]ClO4. Addition of [PPh3(CH2Ph)]X (X = Cl), NaX (X = Br), or KX (X = l, CN, or O2CMe), to the cationic complex leads to the corresponding neutral complexes [Au(pap)2X]. Reaction of [Au(pap)2]ClO4 with [NMe4][AuCl4], leads to [Au(pap)2][AuCl4]. By reacting the neutral acetato-complex with [Hpy]ClO4(Hpy = pyridinium), [Au(pap)2(py)]ClO4 is prepared. The crystal structure of [Au(pap)2][AuCl4] has been determined and shows that the cation has a square-planar co-ordination with two cis-nitrogen [Au–N = 2.17(2)Å(av.)] and two cis-carbon [Au–C = 2.00(2)Å(av.)] atoms bonded to gold.