Functionalization of linear and cyclic siloxanes and a dendritic carbosilane with (η5-C5H5)Fe(CO)2Si(CH3)2CHdouble bond; length as m-dashCH2 via hydrosilylation reaction

A series of multimetallic systems containing silicon-linked cyclopentadienyl dicarbonyl iron moieties including carbosilane dendrimers and cyclic and polymeric siloxanes have been prepared using hydrosilylation reactions. For this purpose the vinyl-substituted silyliron complex (η5-C5H5)Fe(CO)2Si(CH3)2 CHdouble bond; length as m-dashCH2 (1) was prepared by salt elimination reaction between Na[(η5-C5H5)Fe(CO)2] and ClSi(CH3)2CHdouble bond; length as m-dashCH2 and fully characterized. Hydrosilylation reaction of 1 with the appropriate Si–H functionalized molecules in the presence of Karstedt catalyst afforded the novel silyl carbonyl iron-functionalized cyclotetrasiloxane 2, dendrimer 3 and copolymer 4, in which the organometallic units are attached to the silicon-based frameworks through a two-methylene flexible spacer. The electrochemical behaviour of compounds 1–4 has been examined in dichloromethane, tetrahydrofuran and acetonitrile solutions using cyclic voltammetry.