An H-Substituted Rhodium Silylene.

Divergent reactivity of organometallic rhodium(I) complexes, which led to the isolation of neutral rhodium silylenes, is described. Addition of PhRSiH (R=H, Ph) to the rhodium cyclooctene complex ( NNN)Rh(COE) (1-COE; NNN=2,5-[iPr P=N(4-iPrC H )] N(C H ) , COE=cyclooctene) resulted in the oxidative addition of an Si-H bond, providing rhodium(III) silyl hydride complexes ( NNN)Rh(H)SiHRPh (R=H, 2-SiH Ph; Ph, 2-SiHPh ). When the carbonyl complex ( NNN)Rh(CO) (1-CO) was treated with hydrosilanes, base-stabilized rhodium(I) silylenes κ -N,N-( NNN)(CO)Rh=SiRPh (R=H, 3-SiHPh; Ph, 3-SiPh ) were isolated and characterized using multinuclear NMR spectroscopy and X-ray crystallography. Both silylene species feature short Rh-Si bonds [2.262(1) Å, 3-SiHPh; 2.2702(7) Å, 3-SiPh ] that agree well with the DFT-computed structures. The overall reaction led to a change in the NNN ligand bonding mode (κ →κ ) and loss of H from PhSiRH , as corroborated by deuterium labelling experiments.