SYNTHESIS, STRUCTURE AND PROPERTIES OF HEXAMETHYLTRISILANE-BRIDGED BISCYCLOPENTADIENYL TETRACARBONYL DIIRON

The reaction of hexamethyltrisilane-bridged biscyclopentadiene C5H5(Si Me2)(3)C5H5 with Fe(CO)(5) in refluxing xylene gave corresponding di-i ron complexes (SiMe2)(3)[eta(5)-C5H4Fe(CO)](2)(mu-CO)(2) (1) together with the (Me2SiSiMe2)[eta(5)-C5H4Fe(CO)](2)(mu-CO)(2) (2) and [Me2Si(e ta(5)-C5H4)Fe(CO)(2)](2) (3). The crystal structure of 1 was determine d by X-ray diffraction. The formation of the latter two products was d iscussed. Studies on the UV spectra of 1 and 2 and with Me2Si[eta(5)-C 5H4Fe(CO)](2)(mu-CO)(2)(4) indicated that the connection of Si-Si bond s with coordinated cyclopentadienyls resulted in significant red shift s in lambda(max) for the UV spectra of 1 and 2. The electrochemistry o f 1, 2 and 4 was also examined. (C) 1998 Elsevier Science S.A. All rig hts reserved.