Amidinatogermylene Complexes of Copper, Silver, and Gold

The synthesis of the first amidinatogermylene derivatives of the three coinage metals, including the first silver halide complex containing a germylene ligand of any type, has been achieved by reacting metal chloride precursors with the very bulky amidinatogermylene Ge( t Bu 2 bzam) t Bu ( t Bu 2 bzam = N, N ′-di( tert -butyl)benzamidinate). The reactions of Ge( t Bu 2 bzam) t Bu with an equimolar amount of MCl (M = Cu, Ag) led to the tetrameric complexes [M 4 (μ 3 -Cl) 4 {Ge( t Bu 2 bzam) t Bu} 4 ] (M = Cu ( 1 ) and Ag ( 2 )), which contain a pseudocubane-type M 4 (μ 3 -Cl) 4 core. A similar reaction with [AuCl(tht)] (tht = tetrahydrothiophene) afforded the linear mononuclear derivative [AuCl{Ge( t Bu 2 bzam) t Bu}] ( 3 ). The ionic digermylene derivatives [M{Ge( t Bu 2 bzam) t Bu} 2 ][BF 4 ] (M = Cu ( 4 ) and Ag ( 5 )) were satisfactorily prepared from the respective reactions of [Cu(MeCN) 4 ][BF 4 ] and Ag[BF 4 ] with two equivalents of Ge( t Bu 2 bzam) t Bu. The Ge-bound tert -butyl group of Ge( t Bu 2 bzam) t Bu plays an important role in stabilizing compounds 1 – 5 against hydrolysis, since, under similar reaction conditions, no pure complexes could be isolated from reactions of the same metal precursors with the chlorogermylene Ge( t Bu 2 bzam)Cl.