Synthesis, Structure, and Photochemistry of Disilyl Derivatives of the Fp (Fp = (η5-C5H5)Fe(CO)2) System: FpMeSi(CH2)4SiMeFp and FpPhMeSiSiMePhFp

Abstract

The synthesis of (1a) is reported (Fp = [(η5-C5H5)Fe(CO)2), along with small amounts of (2). Photolysis of 1a with a medium-pressure Hg lamp for 8 h resulted in the formation of two different types of intermediate silylene-bridged complexes, [(η5-C5H5)Fe(CO)]2(μ-CO)(μ-SiMeSi(CH2)4) (4) and (5), each existing as a mixture of three equilibrating geometrical isomers, respectively; 4 slowly photoisomerized to the isomers 5 prior to expulsion of the second CO group. Prolonged irradiation of 5 gave a mixture of the cis and trans isomers of the bis(silylene)-bridged complex [(η5-C5H5)Fe(CO)]2(μ-SiMe2)(μ-Si(CH2)4) (6). Similar photolysis of FpMePhSiSiPhMeFp (3) resulted in the sequential formation of the mono(silylene)diiron complex [(η5-C5H5)Fe(CO)]2(μ-CO)(μ-SiMeSiMePh2) (7) and the bis(silylene)diiron complex [(η5-C5H5)Fe(CO)]2(μ-SiPh2)(μ-SiMe2) (8). The molecular structures of 1a, 5a, and 6a have been determined by X-ray diffraction analysis.