Synthesis and structure of a tungsten dichlorosilyl dihydride complex

The reaction of the donor-stabilized silylene complex cis-Cp^*(CO)₂(H)W{double bond, long}SiHPh · THF (3, Cp^* = η⁵-C₅Me₅) with LiAlH₄ followed by the protonation of the resulting Li[Cp^*(CO)₂W(H)(SiH₂Ph)] (4) with excess CF₃COOH afforded the trihydride complex Cp^*(CO)₂WH₃ (6). The structure of 6 was characterized using variable-temperature NMR studies and X-ray crystal analysis. Deprotonation of 6 with KH gave the anionic dihydride complex K[Cp^*(CO)₂WH₂] (7), which was converted into the dichlorosilyl dihydride complex Cp^*(CO)₂W(H)₂(SiHCl₂) (8) on treatment with trichlorosilane. The X-ray crystal analysis of 8 revealed that it adopts a distorted pseudo-octahedral structure with a short W-Si bond, long Si-Cl bonds, and short contacts between the hydrides and silicon atom. Along with these structural features, the conformation of the silyl ligand around the W-Si bond may suggest the presence of a double interligand hypervalent interaction between the dichlorosilyl and hydrides ligands.