The carbenecomplexes (CO)5WC(OEt)SiPh3(1) and (CO)5WC(NEt2)SiPh3(2) thermallydecompose to give triphenylsilane, ethylene, and W(CO6) or (CO)5WCNEt, respectively, while in the presence of moist CO, [Ph3Si(EtO)CHC(O)]2O is formed, believed to arise via the ketene intermediate, Ph3Si(EtO)CCO.