Preparation of Silanediyl-Bridged Fe-Fe and Fe-W Dinuclear Complexes. X-Ray Structures of [Cp~* Fe (CO)(μ-CO){μ-Si (H) CHPh_2}(CO)_nMCp](CP~* = C_5Me_5, Cp = C_5H_5, M = Fe, n = 1; M = W, n = 2)

摘要

Photolysis of a 2:1 mixture of [Cp~*Fe (CO)_2Me] and Ph_2CHSiH_3 produces mainly the monouclear silyl complex [Cp~*Fe (CO)_2{Si (H)_2 CHPh_2}](1) together with two silanediyl-bridged diiron complexes: cis-and trans-[Cp~*_2(CO)_2Fe_2(μ-CO){μ-Si (H) CHPh_2}](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 ℃. Photolysis of [CpFe (CO)_2SiMe_3] or [CpW (CO)_3 Me] in the presence of 1 produces novel silanediyl-bridged complexes [Cp~*Fe(CO)(μ-CO){μ-Si (H) CHPh_2}(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)° incomplex 4.