Synthesis and Properties of a New Kinetically Stabilized Digermyne: New Insights for a Germanium Analogue of an Alkyne

The reduction of an overcrowded (E)-1,2-dibromodigermene, Bbt(Br)GeGe(Br)Bbt (2) [Bbt = 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl], with KC8 afforded a stable digermyne, BbtGe⋮GeBbt (1). The Ge⋮Ge triple-bond characters of 1 were revealed by the X-ray crystallographic analysis and spectroscopic studies (UV/vis and Raman spectra) together with theoretical calculations. The Ge⋮Ge bond lengths of the two nonidentical molecules of 1 observed in the unit cell were shorter than that of the previously reported digermyne, Ar‘Ge⋮GeAr‘ (Ar‘ = 2,6-Dip2C6H3, Dip = 2,6-diisopropylphenyl).