Synthesis, characterisation and substitution reactions of gold(III) C,N-chelates

Abstract

New complexes of the type [AuCl₂L] have been prepared, where L is a chelate consisting of a phenyl group bearing an N-donor substituent (oxazoline and/or dimethylaminomethyl). The structures of two of these, together with that of [AuCl{C₆H₃(CH₂NMe₂)₂-2,6}]₂[Hg₂Cl₆], have been determined by X-ray crystallography; the gold atoms exhibit strict square-planar geometry in all cases. The chloride ligands undergo ready substitution by other halides, thiocyanate, acetate or diethyldithiocarbamate. The monodithiocarbamate complexes [Au(S₂CNEt₂)L]⁺ contain chelated S₂CNEt₂ groups whereas in [Au(S₂CNEt₂)₂L] the L ligand is monodentate (through C), one S₂CNEt₂ is monodentate, the other bidentate; in solution the two S₂CNEt₂ ligands appear equivalent on the NMR time-scale, indicating a rapid equilibrium between the two possible forms.