SYNTHESIS AND PROPERTIES OF (ETA(4)-SILATRIMETHYLENEMETHANE)IRON AND (ETA(4)-SILATRIMETHYLENEMETHANE)RUTHENIUM COMPLEXES

(eta(4)-Silatrimethylenemethane (STMM))iron and -ruthenium complexes M (CO)(3)[eta(4)-Mes(2)-SiC(CH2)((Z,E)-CH(t)Bu)](M = Fe, (Z/E)-2; M = Ru , (Z/E)-5) and Fe(CO)(3)[eta(4)-Mes(2)SiC(CMe(2))(2)-(C=CMe(2))] (4) w ere prepared by reactions of alkylidenesiliranes ((Z/E)-1 and 3) with the corresponding metal carbonyls and characterized spectroscopically. The eta(4)-silatrimethyl-enemethane structures of (Z)-2 and 4 were fu rthermore determined by X-ray crystal analysis. Nevertheless, when (Z) -1 was converted with Ru-3(CO)(12), the trinuclear hydride complex Ru- 3(CO)(9)[mu(3)-Mes(2)Si(C=CH(t)Bu)C2O](mu-H)(2) (6) was obtained as th e major product. 6 exhibits a 1-oxa-2-silacyclopentene unit as a mu(3) -bridging ligand, as has been confirmed by X-ray crystal analysis. The formation of 6 demands a unique metal bond CO insertion into the sili rane ring.