Synthesis of mixed diarylgold(III) complexes. Crystal structure of cis-[2-(phenylazo)phenyl][2-{(dimethylamino)methyl}phenyl]gold(III) tetrachloroaurate

The reaction (1 : 1) between [A u(2-C6H4CH2N Me2)Cl2] and [Hg(2-C6H4-NNPh)2] gives the complex [(2-PhNNC6H4)A u(2-C6H4CH2N MeC2)Cl], which on treatment with AgClO4 gives [(2-Ph NNC6H4)A u(2-C6H4CH2N Me2)]ClO4. From this complex, the species [(2-PhNNC6H4)A u(2-C6H4CH2N Me2)X] (X  CH3COO, CN), or [(2-PhNNC6H4)A u(2-C6H4CH2N Me2)L] (L  PPh3, py) are obtained by reaction with the corresponding KX salts or neutral ligands. The crystal structure of [(2-Ph NNC6H4)A u(2-C6H4CH2N Me2)][AuCl4] (obtained by metathesis between the corresponding perchlorate and tetramethylammonium salts) has been determined; the cation displays square-planar coordination with two cis-nitrogen (AuN: 2.166(15), 2.140(14) Å) and two cis-carbon (AuC: 2.021(16), 2.033(17) Å) atoms bonded to the gold atom.