INTERMOLECULAR FORCES EXPRESSED IN 1,2-DICHLOROETHANE-WATER PARTITION-COEFFICIENTS - A SOLVATOCHROMIC ANALYSIS

The molecular parameters and intermolecular forces controlling partiti on coefficients (P) in the 1,2-dichloroethane (DCE)-water system have been studied. A set of 44 solutes was selected to allow a regular and broad exploration of property spaces. Log P-dee values were measured b y the shake-flask method, centrifugal partition chromatography, and/or the pH-metric method. Linear solvation Gibbs-energy relationship (LSE R) analyses showed that log P-dee values are controlled by the molecul ar volume of the solutes and by their H-bonding donor acidity and acce ptor basicity, with a contribution from the latter parameters signific antly greater than in n-octanol-water partition coefficients. The DCE- water system appears as a promising alternative to the alkane-water sy stem for obtaining partition coefficients of interest in structure-per meation relationship studies.