Structure of aqueous solutions of group IIIA metals perchlorates by near infrared spectroscopy

The state of water in aqueous solutions of group IIIA metal perchlorates at 25°C was studied by the IR spectroscopy in the range of 5400–7500 cm−1. The optical density values of the solution measured at different wavelengths were combined in a matrix of experimental data of the uniform dimension. The matrices were chemometrically analyzed. A number, spectra, and concentration profiles of the spectral forms existing in the solution were determined. By the principal component method, the IR spectra of the studied systems are grouped into the mathematical clusters according to the nature of the cation-water interaction in the solution. The combined use of the infrared spectroscopy and chemometric analysis showed that the structural changes in the solution predicted by the generalized phenomenological model are due to the existence and interconversion of the spectral forms.