Synthesis and structure of a tungsten dichlorosilyl dihydride complex

The reaction of the donor-stabilized silylene complex cis-Cp¹(CO)₂(H)WSiHPh · THF (3, Cp¹ = η⁵-C₅Me₅) with LiAlH₄ followed by the protonation of the resulting Li[Cp¹(CO)₂W(H)(SiH₂Ph)] (4) with excess CF₃COOH afforded the trihydride complex Cp¹(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[Cp¹(CO)₂WH₂] (7), which was converted into the dichlorosilyl dihydride complex Cp¹(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.