Tris(mercaptoimidazolyl)borate complexes of the coinage metals: syntheses and molecular structures of the first gold compounds and related copper and silver derivatives

Abstract

The first tris(mercaptoimidazolyl)borate complexes of gold, Au(Tm^tBu) and (Tm^tBu)Au(PPh₃), have been prepared and structurally characterized. Together with their copper and silver analogues M(Tm^tBu) and (Tm^tBu)M(PPh₃) (M = Cu, Ag), these compounds constitute the first two complete series of Tm^R derivatives to be isolated for the coinage metals. In order to evaluate the steric and electronic effects of the bulky tert-butyl substituents in these species, comparative structural analyses with the known methyl-substituted analogue Ag(Tm^Me) and various (Tm^Me)M(PR₃) derivatives (M = Cu, Ag) are also presented.