Activation of CS₂ and CO₂ by Silylium Cations

Abstract

The hydride‐bridged silylium cation [Et3Si−H−SiEt3]+, stabilized by the weakly coordinating [Me3NB12Cl11]− anion, undergoes, in the presence of excess silane, a series of unexpected consecutive reactions with the valence‐isoelectronic molecules CS2 and CO2. The final products of the reaction with CS2 are methane and the previously unknown [(Et3Si)3S]+ cation. To gain insight into the entire reaction cascade, numerous experiments with varying conditions were performed, intermediate products were intercepted, and their structures were determined by X‐ray crystallography. Besides the [(Et3Si)3S]+ cation as the final product, crystal structures of [(Et3Si)2SMe]+, [Et3SiS(H)Me]+, and [Et3SiOC(H)OSiEt3]+ were obtained. Experimental results combined with supporting quantum‐chemical calculations in the gas phase and solution allow a detailed understanding of the reaction cascade.

Reactions of a diborylstannylene with CO2 and N2O: diboration of carbon dioxide by a main group bis(boryl) complex

“…1 A wide range of transition metal and main group element compounds has been implicated in such transformations in catalytic or stoichiometric fashion. 2 Within group 13-15 chemistry, Frustrated Lewis Pairs (FLPs) have emerged as a novel strategy for CO 2 capture/transformation, 3 as have approaches involving insertion into E-H bonds to produce formate derivatives, which can be reduced further (even as far as methane) by using an appropriate hydride source (e.g., for E = Al(III), 4 Ga(III), 5 Si(IV), 6 Ge(II)). 7 Another approach is to employ multiply-bonded compounds, which have been shown to give double-insertion products, 8 either reversibly (Ga=P) 8a or irreversibly (Al=Te).…”