Organopolysilane oligomers bearing transition-metal moieties: Synthesis, reactivities and molecular structure of [η5-me3sime2sic5h 4(co)fe(co)2fe(co)-η5-c5h 4sime2sime3]

Article abstract of DOI:10.1016/0277-5387(96)00193-3

Reaction of Me₃SiMe₂SiC₅H₅ (4), prepared from Me₃SiMe₂SiCl and C₅H₅Na, with Fe(CO)₅ in refluxing xylene afforded the title compound (3). The silicon-silicon bond in 3 is exceptionally stable in refluxing xylene and also in succeeding reactions to prepare a series of its derivatives. Thus, 3 reacted with I₂ in either chloroform or benzene, giving [η⁵-Me₃SiMe₂SiC₅H ₄Fe(CO)₂I] (6). Compound 3 was reduced by sodium amalgam and reacted subsequently with CH₃I, PhCH₂Cl, CH₃COCl, PhCOCl, Cy₃SnCl (Cy = cyclohexyl) and Ph₃SnCl, producing [η⁵-Me₃SiMe₂SiC₅H ₄Fe(CO)₂R] [7 : R = CH₃ (a), PhCH₂ (b), CH₃CO (c), PhCO (d), Cy₃Sn (e) and Ph₃Sn (f), respectively]. The molecular structure of 3 has been determined by X-ray diffraction crystallography. It was found that 3 has a transconfiguration with a symmetrical centre located at the middle of the Fe - Fe bond. It is abnormal that the conformation of the disilane part around the Si - Si bond is almost eclipsed rather than staggered. Copyright