Siliciumhaltige Carben-Komplexe: IX. Thermische Fragmentierung von Alkoxy(triphenylsilyl) carben-Komplexen, (CO) 5MC(OR)SiPh 3 (M = Cr, Mo, W)

Abstract

On thermolysis of (CO) 5MC(OEt)SiPh 3 (M = W, Mo, Cr) in the solid state or in solution three different decomposition pathways are observed, which are unusual for Fischer-type carbene complexes: fragmentation of the complex to give triphenylsilane, ethylene and M(CO) 6, formation of ethyl(triphenylsilyl)ketone and decomposition to give ethyltriphenylsilane and M(CO) 6. The proportions of reactants which follow each reaction path depend on the metal and on the reaction conditions; in any case the formation of ethyltriphenylsilane is the less-favoured. In contrast, when (CO) 5WC(OMe)SiPh 3 is heated either in the solid state or in solution, MeSiPh 3 and W(CO) 6 are formed almost exclusively.