Dipole Moment Derivative Signs, Polar Tensors, And Vibrational Intensities Of C2f6

The atomic polar tensors of hexafluoroethane calculated from the experimental vibrational intensities measured previously are reported. Dipole moment derivative signs were determined using STO-3G and 4-31G molecular orbital wave functions. The fluorine polar tensor invariants, p̄, β, and χ, are found to be significantly smaller than those for fluorine of the substituted fluoromethanes. Transference of fluorine polar tensor elements from CH3F and CF4 to C2F6 results in reasonably accurate estimates for the C2F6 vibrational intensities with the exception of the one for the v7 E symmetry CF stretching mode, which is calculated to be much too large. © 1989 American Chemical Society.9382957295