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

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.

W(PMe3)4(η2-CH2PMe2)H 与 PhSiH3 反应，首次合成了二苯基硅基化合物，即 W(PMe3)4(SiH2SiHPh2)H3 和 W(PMe3)3(SiH2Ph)(SiH2SiHPh2)H4，其反应机理涉及 SiHPh2 基团的迁移至硅烯配体。除上述单核化合物外，W(PMe3)4(η2-CH2PMe2)H 与 PhSiH3 的反应还产生了一种新颖的二核化合物 [W(PMe3)2(SiHPh2)H2](μ-Si,P-SiHPhCH2PMe2)(μ-SiH2)[W(PMe3)3H2]，该化合物含有桥连的硅烯配体，能与两个钨中心形成 3-中心-2-电子相互作用。[W(μ-H)-Si(μ-H)-W] 核心的成键可通过多种共振结构来描述，其中部分结构在钨与硅之间存在多重键特性。值得注意的是，[W(PMe3)2(SiHPh2)H2](μ-Si,P-SiHPhCH2PMe2)(μ-SiH2)[W(PMe3)3H2] 具有已报道的最短的 W-Si 键长。W(PMe3)4(η2-CH2PMe2)H 与 Ph2SiH2 的相应反应则生成 σ-硅烷化合物，即 W(PMe3)3(σ-HSiHPh2)H4。