Vibrational and orientational relaxation of polyatomic anions in aqueous solutions by raman spectroscopy

Analysis of the vibrational and orientational relaxation of polyatomic anions, referring to the type of spherical top СlО₄⁻, AsF₆⁻, PO₄3; SO₄2;⁻, and of symmetrical top CF₃SO₃⁻, SO₃2;⁻, NO₃⁻, HPO₄2;⁻ in aqueous solutions according to the Raman spectroscopy data is presented. It is demonstrated that the anion-cation interaction results in a considerable decrease of the vibrational relaxation time and in changingof phase modulation mechanism. The conclusion that the formation of the ion-molecular H-bond and theinteraction of anions with cations is concluded to lead to hindering of the anion orientational motion is drawn.