Hydrogen-substituted osmium silylene complexes: effect of charge localization on catalytic hydrosilation.

Addition of bulky primary silanes to the osmium benzyl compound, Cp*(iPr3P)OsCH2Ph, afforded two neutral hydrogen-substituted silylene complexes via activation of two Si-H bonds. These species have been structurally characterized, and their reactivity has been examined experimentally and computationally. Comparison of these neutral silylene complexes with their cationic analogue highlights the dramatic influence of charge distribution on the reaction chemistry of metal silylene complexes.