The dimeric hydrido complex [Y(L)(THF)(mu-H)](2)() containing the CH(2)SiMe(2)-linked amido-cyclopentadienyl ligand L = C(5)Me(4)CH(2)SiMe(2)NCMe(3)(2-) catalyzed the hydrosilylation of 1,5-hexadiene, 1,7-octadiene and vinylcyclohexene by PhSiH(3). As demonstrated for 1,7-octadiene, the product distribution of the hydrosilylation strongly depends on the molar ratio of the reagents. In the absence of PhSiH(3), the stoichiometric reaction of with 1,5-hexadiene gave the isolable crystalline cyclopentylmethyl complex [Y(L)[CH(2)CH(CH(2))(4)](THF)]. Internal olefins such as trans-stilbene and alkynes such as tert-butylacetylene were not hydrosilylated by. trans-Stilbene was inserted into the yttrium-hydride bond of to give the 1,2-diphenylethyl complex [Y(L)[CH(CH(2)Ph)Ph](THF)]. tert-Butylacetylene reacted with to give the dimeric acetylide [Y(L)(C[triple bond]CCMe(3))](2). In an attempt to detect the monomeric hydrido species as a DME adduct [Y(L)H(DME)], complex was reacted with DME to form the sparingly soluble, dimeric 2-methoxyethoxy complex [Y(L)(mu-OCH(2)CH(2)OMe-kappaO)](2) under C-O splitting.