Raman and Infrared Spectral Studies of Aqueous Calcium Nitrate Solutions

Abstract

Extensive Raman and infrared spectral data have been obtained from studies of aqueous solutions of Ca(NO3)2, as well as from mixtures involving high Ca2+–NO3− or NO3−–Ca2+ concentration ratios. The removal of the degeneracy of the E′ modes, even in dilute solution, and the activity of the A′ mode in the infrared spectrum suggest that the symmetry of the nitrate ion has been lowered by solvation with water. The perturbation is enhanced by ionic interaction with hydrated calcium ions. The implications of the model are discussed.