σ‑Silane, Disilanyl, and [W(μ‑H)Si(μ‑H)W] Bridging Silylene Complexes via the Reactions of W(PMe3)4(η2‑CH2PMe2)H with Phenylsilanes
datasetposted on 31.12.2014, 00:00 by Ashley A. Zuzek, Michelle C. Neary, Gerard Parkin
W(PMe3)4(η2-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.