ASSESSMENT OF SOLVENT PARAMETERS AND THEIR CORRELATION WITH PROTONATION CONSTANTS IN DIOXANE WATER MIXTURES USING FACTOR-ANALYSIS

The effect of the composition of dioxane-water mixtures on wavelength shifts of different solvatochromic indicators and on pK(a) values of different carboxylic acids are studied using factor analysis. Target factor analysis is subsequently applied to find out which are the physicochemical parameters affecting the observed data variation. For wavelength shifts of the selected solvatochromic indicators three main sources of variation are found: solvent polarity, pi-*, the hydrogen-bond donor acidity of solvent, alpha, and the hydrogen-bond acceptor basicity of the solvent, beta. For pK(a) values of carboxylic acids the main source of variation is identified as being the polarity of the mixed solvent.