Factor analysis as a complement to band resolution. V. Complexing of pentachlorophenol and acetone in carbon tetrachloride solution

Abstract

Complex formation between pentachlorophenol and acetone and acetone-d₆ in carbon tetrachloride solution has been studied in both the hydroxyl and carbonyl stretching regions of the infrared spectrum. Factor analysis of the digitized spectra indicates three absorbing components for each set of solutions in the hydroxyl stretching region. Concentration studies revealed roughly linear relationships between the areas of the 'free' ν(OH) band and both of the resolved complex bands, suggesting that two different 1:1 complexes occur in CCl₄ solution. In the ν(CO) region only one band due to complex formation was detected. Equilibrium constants for the isotopically different complexes at about 30 °C are reported. In the hydroxyl stretching region, band resolution was also carried out using four components which gave a better fit to the observed spectrum. A set of equilibrium constants were then obtained. However, considerable difficulties were met in the calculations and in the interpretation of these results, so that the three band, two complex model is preferred.