SYNTHESIS AND CHARACTERIZATION OF 1-TRANSITION METAL-COMPLEX SUBSTITUTED-2,3,4,5-TETRAPHENYL-1-SILACYCLOPENTADIENYL COMPLEXES AND GENERATION OF TRANSITION-METAL COMPLEX-SUBSTITUTED SILYLENE

New silicon-monosubstituted (eta4-2,3,4,5-tetraphenyl-1-silacyclopentadiene)transition metal complexes are described. (7-Alkyl-7-silanorbornadienyl)MLn(Alkyl = Methyl : MLn = CpRu(CO)2 : Alkyl = Methyl : MLn = CpNi(CO) : Alkyl = Ethyl : MLn = CpNi(CO) complexes were prepared from the corresponding silole-transition metal complexes with dimethyl acetylenedicarboxylate. Cycloaddition products were obtained with 2,3-dimethyl-1,3-butadiene, 2,3-butanedione, and 1,4-benzoquinone through the ruthenium-substituted silylene. We have determined the crystal structure of (1-methyl-2,3,4,5-tetraphenyl-1-silacyclopentadienyl)cyclopentadienyldicarbonylruthenium by using graphite monochromated Mo-Ka radiation. The compound was crystallized in the monoclinic space group P2(1)/c with a = 9.838(1), b = 15.972(3), c = 18.327(3) angstrom, and beta=94.28(1)degrees. The ruthenium moiety CpRu(CO)2 on silicon is in an axial position.