Poly(imidazolyliden-yl)borato Complexes of Tungsten: Mapping Steric vs. Electronic Features of Coordinating Ligands.

A convenient synthesis of [HB(HImMe)](PF) (ImMe = -methylimidazolyl) is decribed. This salt serves in situ as a precursor to the tris(imidazolylidenyl)borate Li[HB(ImMe)] pro-ligand upon deprotonation with BuLi. Reaction with [W(≡CCHMe-4)(CO)(pic)(Br)] (pic = 4-picoline) affords the carbyne complex [W(≡CCHMe-4)(CO){HB(ImMe)}].