Molecular and electronic structures of germylene and stannylene complexes (CO)5MECl2 · nTHF (M = Cr, W; E = Ge, Sn; n = 1, 2) as studied by IR and Raman spectroscopy, X-ray analysis, and quantum chemistry

摘要

The Raman and IR spectra of the complexes (CO)5CrSnCl2 · THF (1), (CO)5WSnCl2 · THF (2), (CO)5CrGeCl2·THF (3), (CO)5WGeCl2·THF (4), (CO)5CrSnCl2·2THF (5), and (CO)5WSnCl2 · 2THF (6) were measured and interpreted using quantum chemical calculations. Complexes 3 and 5 were characterized by X-ray analysis. The stretching vibrations of the CO groups in the spectra of solutions of complexes 1-6 obey the selection rules for C_(4v) local symmetry. For the complexes containing 0 (type A), 1 (type B), and 2 (type C) THF molecules, a comparison was made of the calculated and experimental M···E~(II) bond lengths and energies, as well as the v(CO) vibrational frequencies. The contribution of the π -component to the M···E~(II) bond decreases in the order A→B→C and leads to enhancement of the donor ability of the carbene-like ligand and to a slight elongation and weakening of this bond. An attempt to grow crystals of complex 6 in air unexpectedly resulted in a polynuclear complex [(CO)5WSn(Cl)(μ-OH)2SnCl2(μ-OH)]2 · 6THF, which was characterized by X-ray analysis and Raman spectroscopy.