Molecular Geometry of Vanadium Dichloride and Vanadium Trichloride: A Gas-Phase Electron Diffraction and Computational Study (original) (raw)

The molecular geometries of VCl 2 and VCl 3 have been determined by computations and gas-phase electron diffraction (ED). The ED study is a reinvestigation of the previously published analysis for VCl 2 . The structure of the vanadium dichloride dimer has also been calculated. According to our joint ED and computational study, the evaporation of a solid sample of VCl 2 resulted in about 66% vanadium trichloride and 34% vanadium dichloride in the vapor. Vanadium dichloride is unambiguously linear in its 4 Σ g þ ground electronic state. For VCl 3 , all computations yielded a Jahn-Tellerdistorted ground-state structure of C 2v symmetry. However, it lies merely less than 3 kJ/mol lower than the 3 E 00 state (D 3h symmetry). Due to the dynamic nature of the Jahn-Teller effect in this case, rigorous distinction cannot be made between the planar models of either D 3h symmetry or C 2v symmetry for the equilibrium structure of VCl 3 . Furthermore, the presence of several low-lying excited electronic states of VCl 3 is expected in the high-temperature vapor. To our knowledge, this is the first experimental and computational study of the VCl 3 molecule.