Synthesis of (C"N, S"S)-cyclometallated phosphonodithiolate gold (III) complexes

Herein we report the complexation of gold(III) with chalcogenophosphorous ligands derived from Lawesson's reagent (LR). The reaction of Lawesson's reagent with (ppy)AuCl2 (ppy = 2-phenylpyridine) led to the novel [Au (ppy){S2P(O)(p-MeO-C6H4)] complexes 4, resulting from the demethylation of the expected [Au(ppy){S2P(MeO) (p-MeO-C6H4)]+ complexes. The novel gold(III) phosphonodithiolate complexes have been studied by HRMS, multinuclear NMR and X-ray crystallography. To the best of our knowledge this is the first reported synthesis of phosphonodithiolate gold(III) complexes of LR and provides a valuable addition to the few examples of gold complexes containing organophosphorus-chalcogen ligands.