Synthesis of Self-Stabilized and Donor-Free Silyl(silylene)tungsten Complexes

Photolysis of Cp‘W(CO)3Me (1a, Cp‘ = η-C5Me5; 1b, Cp‘ = η-C5Me4Et) in the presence of excess
HSiMe2SiMe3 afforded a self-stabilized silyl(silylene)tungsten complex with a dimeric structure, [Cp‘W(CO)2(SiMe2)(SiMe3)]2 (2a, Cp‘ = η-C5Me5; 2b, Cp‘ = η-C5Me4Et), respectively. In contrast, photolysis of 1a in
the presence of HSiMe2SiMeMes2 (Mes = 2,4,6-Me3C6H2)
resulted in the formation of the first donor-free silyl(silylene) complex with only alkyl and aryl substituents
on the silicon atoms, Cp‘W(CO)2(SiMes2)(SiMe3) (3).