GAS-LIQUID CHROMATOGRAPHIC STUDY OF THERMODYNAMICS OF SOLUTION OF SOME AROMATIC COMPOUNDS .3. SOLUTIONS AND ASSOCIATIVE INTERACTION WITH TETRACHLOROTEREPHTHALATE ESTERS

The elution characteristics of several different types of isomeric aromatic compounds from columns containing di-n-alkyl tetrachloroterephthalate esters are reported. Propyl, butyl, amyl, and octyl esters were studied at 100 and 110°. Results are discussed in terms of excess partial molar thermodynamic quantities and compared with a treatment which assumes associative interaction between the aromatic solutes and the tetrahalogenated aromatic nuclei incorporated in the stationary phases. The two approaches are found to be similar and sometimes complementary in characterizing solute-solvent interactions. It is shown that the behavior of mixed solvents containing tetrahalogenated esters may sometimes depend on the type of solute involved and the nature of the solute-solvent interaction. It was found that the tetrachloroterephthalate esters are unusually selective for the separation of m- and p-methylethylbenzenes.