Preparation of Silanediyl-Bridged Fe–Fe and Fe–W Dinuclear Complexes. X-Ray Structures of [Cp^*Fe(CO)(μ-CO){μ-Si(H)CHPh₂}(CO)_nMCp] (Cp^*= C₅Me₅, Cp = C₅H₅, M = Fe,n= 1; M = W,n= 2)

Photolysis of a 2 : 1 mixture of [Cp*Fe(CO)2Me] and Ph2CHSiH3 produces mainly the mononuclear silyl complex [Cp*Fe(CO)2{Si(H)2CHPh2}] (1) together with two silanediyl-bridged diiron complexes: cis- and trans-[Cp*2(CO)2Fe2(μ-CO){μ-Si(H)CHPh2}] (2), and [{Cp*Fe(CO)2}2]. The trans-2 complex isomerizes to cis-2 photochemically, but no cis–trans isomerization occurs thermally below 100 °C. Photolysis of [CpFe(CO)2SiMe3] or [CpW(CO)3Me] in the presence of 1 produces novel silanediyl-bridged complexes [Cp*Fe(CO)(μ-CO){μ-Si(H)CHPh2}(CO)nMCp] (3: M = Fe, n = 1; 4: M = W, n = 2) in moderate yields. Complexes 3 and 4 have been characterized by X-ray diffraction analysis. To the best of our knowledge, complex 4 is the first example of a silanediyl-bridged Fe–W complex. The Cp and Cp* rings are mutually cis with the dihedral angle of 78.7(2)° in complex 3, but they are trans with the dihedral angle of 13.1(6)° in complex 4.