Oxidative coupling of silylated nonagermanide clusters

Abstract

Polyhedral main group element clusters of tetrel elements are discussed as suitable building units to form atom-precise nano-structures. Herein we report the oxidative coupling of two [Ge₉{Si(TMS)₃}₂]²⁻ clusters (TMS = trimethylsilyl) resulting in the dimeric cluster [Ge₉{Si(TMS)₃}₂]₂²⁻. The dimer is structurally characterized as the [NHC^iPrCu]⁺ adduct {NHC^iPrCu[Ge₉{Si(TMS)₃}₂]}₂ [NHC^iPr = 1,3-di(isopropyl)imidazolylidine]. The linkage of two molecular [Ge₉{Si(TMS)₃}₂]²⁻ anions under formation of an exo Ge–Ge bond occurs in the presence of Cy₂BCl (Cy = cyclohexyl) and is mediated by trace amounts of oxygen as indicated by the isolation of the by-product Cy₂B-O-BCy₂.