Raman intensities, vibrational eigenvectors, electro‐optical parameters and force constants of SO₄²⁻, ClO₄⁻, PO₄³, CO₃²⁻ and NO₃⁻ anions in polycrystalline samples

The relative Raman intensities of the fundamental vibrational modes of the tetrahedral oxoanions SO 4 2− , ClO 4 − , PO 4 3 and of the plane trigonal oxoanions CO 3 2− and NO 3 − have been measured from polycrystalline samples. Using the bond polarizability theory, the vibrational eigenvectors of F 2 ( T d ) and E ' ( D 3 h ) species of these anions in different crystalline environments are derived from the above Raman intensity data. The results are consistent with those obtained through Wilson's GF method, although there exists a multiplicity of solutions. Relative values of SO, ClO, PO and NO bond polarizability parameters are reported. Comparison of these results with liquid state absolute values from the literature enables us to suggest a standard for measuring absolute Raman intensities in the solid phase.