SOLVENT EFFECTS ON THE DISSOCIATION OF ALIPHATIC CARBOXYLIC-ACIDS IN WATER-N,N-DIMETHYLFORMAMIDE MIXTURES - CORRELATION BETWEEN ACIDITY CONSTANTS AND SOLVATOCHROMIC PARAMETERS

The acid dissociation constants of nine aliphatic carboxylic acids in several N,N-dimethylformamide-water mixtures were subjected to factor analysis (FA) and two solvent factors emerged. A further target factor analysis (TFA) indicated that the Kamlet and Taft general equation is reduced in these mixtures to two terms: the independent one and that related to the hydrogen bond acceptor (HBA) basicity beta solvatochromic parameter. Accordingly, an excellent correlation is found between the logarithmic values of the acidity constants of each acid in the binary mixtures and their corresponding beta values.