Models for Liquid–Liquid Partition in the System Ethanolamine-Organic Solvent and Their Use for Estimating Descriptors for Organic Compounds

Partition coefficients for varied compounds were determined for the ethanolamine–organic solvent biphasic partition systems where the organic solvent is n-heptane or isopentyl ether. These partition coefficient databases are analyzed using the solvation parameter model facilitating a quantitative comparison of the ethanolamine-based partition system with other totally organic partition systems. Ethanolamine is a cohesive solvent, reasonably dipolar/polarizable, strongly hydrogen-bond basic, and moderately hydrogen-bond acidic. Ethanolamine–organic solvent systems afford a complementary approach to other totally organic biphasic partition systems for sample preparation and descriptor measurements for compounds of low water solubility. In particular, ethanolamine is a stronger hydrogen-bond base than other polar organic solvents and water and forms biphasic systems that should be well suited to measuring the hydrogen-bond acidity descriptor and for the selective extraction of hydrogen-bond acids soluble in n-heptane or isopentyl ether.