An H-Substituted Rhodium Silylene |
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Authors: | Connor S. MacNeil Prof. Dr. Paul G. Hayes |
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Affiliation: | Canadian Centre for Research in Advanced Fluorine Technologies (C-CRAFT), Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive W, Lethbridge, T1K 3M4 Canada |
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Abstract: | Divergent reactivity of organometallic rhodium(I) complexes, which led to the isolation of neutral rhodium silylenes, is described. Addition of PhRSiH2 (R=H, Ph) to the rhodium cyclooctene complex (iPrNNN)Rh(COE) (1-COE; iPrNNN=2,5-[iPr2P=N(4-iPrC6H4)]2N(C6H2)−, COE=cyclooctene) resulted in the oxidative addition of an Si−H bond, providing rhodium(III) silyl hydride complexes (iPrNNN)Rh(H)SiHRPh (R=H, 2 -SiH2Ph; Ph, 2 -SiHPh2). When the carbonyl complex (iPrNNN)Rh(CO) ( 1 -CO) was treated with hydrosilanes, base-stabilized rhodium(I) silylenes κ2-N,N-(iPrNNN)(CO)Rh=SiRPh (R=H, 3 -SiHPh; Ph, 3 -SiPh2) 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 -SiPh2] that agree well with the DFT-computed structures. The overall reaction led to a change in the iPrNNN ligand bonding mode (κ3→κ2) and loss of H2 from PhSiRH2, as corroborated by deuterium labelling experiments. |
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Keywords: | H-substituted silylene hydrosilation catalysis metal–ligand cooperativity pincer ligands rhodium |
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