Synthesis, characterization, and electronic structures of a methyl germyliumylidene ion and germylone-group VI metal complexes

Abstract

The reaction of germylone (L)Ge (1) [L = 3-Ad-1-{C(^tBu) = N(Mes)}C₃H₄N₂] with 1 equivalent of MeOTf afforded a germyliumylidene ion [(L)GeMe]⁺OTf⁻ (2), while reactions with M(CO)₅(thf) (M = Cr, Mo, W) gave the corresponding germylone-metal complexes [(L)Ge]M(CO)₅ (3–5). The former possesses a pyramidal Ge center, whereas the latter display a planar geometry around the Ge atom. Computational studies showed a unique bonding interaction between 1 and the M(CO)₅ unit, which involves a σ-donation as well as a weak π-back-donation.