American Chemical Society
ja510703s_si_003.cif (1.68 MB)

σ‑Silane, Disilanyl, and [W(μ‑H)Si(μ‑H)W] Bridging Silylene Complexes via the Reactions of W(PMe3)42‑CH2PMe2)H with Phenylsilanes

Download (1.68 MB)
posted on 2014-12-31, 00:00 authored by Ashley A. Zuzek, Michelle C. Neary, Gerard Parkin
W­(PMe3)42-CH2PMe2)H reacts with PhSiH3 to give the first examples of diphenyl­disilanyl compounds, W­(PMe3)4­(SiH2SiHPh2)­H3 and W­(PMe3)3­(SiH2Ph)­(SiH2SiHPh2)­H4, via a mechanism that is proposed to involve migration of a SiHPh2 group to a silylene ligand. In addition to the formation of the afore­mentioned mono­nuclear compounds, the reaction of W­(PMe3)4­(η2-CH2PMe2)­H with PhSiH3 also yields a novel dinuclear compound, [W­(PMe3)2­(SiHPh2)­H2]­(μ‑Si,P-SiHPh­CH2PMe2)­(μ‑SiH2)­[W­(PMe3)3H2], which features a bridging silylene ligand that participates in 3-center-2-electron interactions with both tungsten centers. The bonding within the [W­(μ‑H)­Si­(μ‑H)­W] core can be described by a variety of resonance structures, some of which possess multiple bond character between tungsten and silicon. In this regard, [W­(PMe3)2­(SiHPh2)­H2]­(μ‑Si,P-SiHPh­CH2PMe2)­(μ‑SiH2)­[W­(PMe3)3H2] possesses the shortest W–Si bond length reported. The corresponding reaction of W­(PMe3)4­(η2-CH2PMe2)H with Ph2SiH2 yields the σ-silane compound, W­(PMe3)3­(σ-HSiHPh2)­H4.