The matrix isolation technique, combined with infrared spectroscopy and theoretical calculations, has been used to investigate VCl_4, as well as its reactions with CH_3OH and its isotopomers. The infrared spectrum of VCl_4 in solid argon showed an intense doublet at 474 and 501 cm~(-1), which is indicative of a splitting of the triply degenerate stretching mode in Td symmetry due to Jahn-Teller distortion. Density functional theory (DFT) calculations (UB3LYP/6-311++g(d,2p)) reproduced this splitting very well. The calculated structure had four equal V-Cl bonds, but with two Cl-V-Cl angles equal to 110.8° and two angles equal to 106.9°. Using twin-jet deposition, the initial intermediate in the reaction of VCl4 with CH_3OH was identified as a 1:1 molecular complex, characterized by perturbations to the V-Cl, C-O, and O-H stretching modes. This complex was destroyed by near-UV irradiation, producing the novel Cl_3VOCH_3 species and cage-paired HCl. Merged-jet co-deposition of CH_3OH and VCl_4, with a room-temperature reaction zone, led to almost-complete conversion to Cl_3VOCH_3. This species was identified by use of isotopic labeling, the observation of HCl as an additional reaction product, and by comparison to DFT calculations. In addition, a large yield of CH_3Cl was observed.
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