Synthesis of Coordinatively Unsaturated Half-Sandwich Iron–Silyl Complexes with an N-Heterocyclic Carbene Ligand and Their Reactions with H2

Synthesis of Coordinatively Unsaturated Half-Sandwich Iron–Silyl Complexes with an N-Heterocyclic Carbene Ligand and Their Reactions with H2:

Abstract

A half-sandwich, coordinatively unsaturated N-heterocyclic carbene complex of iron with a metallacycle was found to cleave the Si–H bonds of hydrosilanes to give 16-electron iron–silyl complexes. The reactions of silyl complexes with H₂ led to the formation of dihydride complexes, in which hydride ligands weakly interact with the silicon atom. The molecular structures of these new complexes have been determined by means of X-ray crystallography.

A half-sandwich, 16-electron iron complex with a cyclometalated N-heterocyclic carbene ligand was found to activate the Si–H bonds of hydrosilanes, thus giving rise to coordinatively unsaturated iron–silyl complexes. The silyl complexes interact with H₂ to form 18-electron dihydride complexes.