Microwave methods for the synthesis of gold(III) complexes

New microwave methods were developed for the synthesis of cationic and neutral gold(III) complexes. Six examples of [AuCl2(N–N)][PF6], containing 2,2′-bipyridine-type ligands, and three examples of AuCl2(C–N), containing cyclometallated 2-phenylpyridine-type ligands, were successfully prepared. Two of the complexes, [AuCl2(5,5′-dimethyl-2,2′-bipyridine)][PF6] and [AuCl2(4,4′,5,5′-tetramethyl-2,2′-bipyridine)][PF6], have not been previously reported. Generally, the microwave-heated reactions gave analytically pure products within minutes – a substantial improvement over conventional procedures. In conjunction, the thermal stabilities of some of the complexes were studied by thermogravimetric analysis. The transformation of AuCl3(2-(p-tolyl)pyridine) into its cyclometallated analog AuCl2(tpy), marked by the loss of a mass corresponding to HCl, was observed.