The preparation and electrochemistry of technetium and rhenium complexes of 2-(diphenylphosphino)benzenethiol. The crystal and molecular structures of [Re(2-Ph2PC6H4S)3] and [Tc(2-Ph2PC6H4S)3]

Abstract Reaction of a variety of rhenium(III) or (V) precursors with the bidentate (1−) mixed phosphino-thiol ligand 2-(diphenylphosphino)benzenethiol (DPPBTH) in mildly alkaline methanol leads to the formation of the 16-electron complex [Re(DPPBT) 3 ] ( I ). With technetium [Tc(DPPBT) 3 ] ( II ), [TcOCl(DPPBT) 2 ] ( III ) or [TcN(DPPBT) 2 ] ( IV ) may be obtained depending on the conditions and starting material. The X-ray crystal and molecular structures of I and II show very similar distortions from ideal geometry due to intra ligand interactions. The complexes have been further studied by cyclic voltammetry and UV-vis spectroscopy.