Addition of Isocyanides to Tetramesityldigermene: A Comparison of the Reactivity between Surface and Molecular Digermenes

The reaction of benzyl isocyanide, tert-butyl isocyanide, and 2,6-dimethylphenyl isocyanide with tetramesityl-digermene (Mes(2)Ge=GeMes(2)) was examined. Whereas the addition of benzyl isocyanide gave the C-NC activation product, Mes(2)Ge(CH2Ph) Ge(CN) Mes(2), tert-butyl isocyanide, and 2,6-dimethylphenyl isocyanide did not give stable ad-ducts, rather the rate of conversion of the digermene to the corresponding cyclotrigermane was accelerated. A comparison between the reactivity of the isocyanides with Mes(2)Ge=GeMes(2) and the Ge(100)-2 x 1 surface was made and some insights into the surface chemistry are offered.