Organometallic silicon-based dendrimers with peripheral Si-cyclopentadienyl, Si-Co and Si-Fe sigma-bonds

The new cyclopentadienyl functionalized dendrimer Si[(CH2)(3)SiMe(2)(C5H5)](4) (1) has been prepared and used to pi-coordinate Co(CO)(2) moieties, affording the tetranuclear Si[(CH2)(3)SiMe(2)(eta(5)-C5H4)Co(CO)(2)](4) (2) The Si-H and Si-Cl functionalized dendrimers Si[(CH2)(3)SiMe(2)H](4) (G1H(1)) and Si[(CH2)(3)SiMe(2)Cl](4) (G1Cl(1)) have been reacted with Co-2(CO)(8) and Na+[(eta(5)-C5H5)Fe(CO)(2)](-), respectively, to yield the corresponding organometallic dendritic molecules Si[(CH2)(3)SiMe(2)Co(CO)(4)](4) (3) and Si[(CH2)(3)SiMe(2)(eta(5)-C5H5)Fe(CO)(2)](4) (4), containing peripheral Si-Co and Si-Fe sigma-bonds.