Synthesis of Bisgermavinylidene and Its Reaction with Chalcogens

The lithium complex [HC(PPh2NSiMe3)2Li(THF)] (2) prepared by the reaction of BunLi
with bis(iminophosphorano)methane reacts with GeCl2·dioxane in different stoichiometric
ratios to afford [HC(PPh2NSiMe3)2GeCl] (3) and [(Me3SiNPPh2)2CGe→GeC(PPh2NSiMe3)2] (4), respectively. Bisgermavinylidene 4 can also be obtained by the reaction of 3
with [Ge{N(SiMe3)2}2] or 2. Further reaction of 4 with Me3NO afforded [(μ-NPh2P)(Me3SiNPh2P)CGe(OSiMe3)]2 (5), and direct reaction of elemental chalcogens (sulfur, selenium,
and tellurium) with 4 afforded [(Me3SiNPPh2)2CGe(μ-E)]2 [E = S (6), Se (7), and Te (8)].
X-ray structures of compounds 2−8 have been determined.