Knowledge Bank

The vibrational spectra of simple contact ion pairs, such as $M+NO3-,M+ClO3-$ and $M+ClO4-$, isolated in argon matrices have been determined in previous $studies.1$ More recently it has been shown that the cation distortion of the anion, as indicated by the magnitude of the splittinge £or the degenerate modes is sharply decreased in glassy water and glassy ammonia $matrices.2$ This phenomenon is attributed to the electron donor action associated with the partial solvation of the metal cations by the matrix molecules. In this paper the step-wise solvation of the cations in the contact ion pairs will be displayed in the variation in magnitude of the splitting of the degenerate modes for the complete range of argon-associating matrix compositions. Certain published liquid solution spectra will be considered in view of the new contact ion pair results.