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 2 (R=H, Ph) to the rhodium cyclooctene complex ( i Pr NNN)Rh(COE) (1‐COE; i Pr NNN=2,5‐[ i Pr 2 P=N(4‐ i PrC 6 H 4 )] 2 N(C 6 H 2 ) − , COE=cyclooctene) resulted in the oxidative addition of an Si−H bond, providing rhodium(III) silyl hydride complexes ( i Pr NNN)Rh(H)SiHRPh (R=H, 2 ‐SiH 2 Ph; Ph, 2 ‐SiHPh 2 ). When the carbonyl complex ( i Pr NNN)Rh(CO) ( 1 ‐CO) was treated with hydrosilanes, base‐stabilized rhodium(I) silylenes κ 2 ‐ N , N ‐( i Pr NNN)(CO)Rh=SiRPh (R=H, 3 ‐SiHPh; Ph, 3 ‐SiPh 2 ) 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 2 ] that agree well with the DFT‐computed structures. The overall reaction led to a change in the i Pr NNN ligand bonding mode (κ 3 →κ 2 ) and loss of H 2 from PhSiRH 2 , as corroborated by deuterium labelling experiments.