Theoretical investigation on the effect of the ligand on bis-silylation of C(sp)–C(sp) by Ni complexes

Density functional theory is used to study the bis-silylation of alkyne catalysed by a transition metal nickel–organic complex. The active catalyst, organic ligand, reaction mechanism, and rate-determining step were discussed with regard to dynamics and thermodynamics. COD or SIPr (COD = cyclooctadiene, SIPr = 1,3-bis(2,6-diisopropyl-phenyl)-4,5-dihydroimidazol-2-ylidene) coordination with Ni will greatly reduce the energy barrier of the Si–Si insertion step, that is, ΔΔG reaches 15.5 kcal mol(−1). Furthermore, the structure of alkynes will change the energy barrier of the alkyne insertion step.