A calorimetric study of complex formation between molecular iodine and pyridine or 2-methylpyridine in weakly polar solvents

Abstract

Heats of solution or dilution of pyridine and 2-methylpyridine in n-hexane, cyclohexane, carbon tetrachloride, benzene, and chlorobenzene and in solution containing iodine have been measured by calorimetry. Equilibrium constants for complex formation of the amines with molecular iodine have been determined by spectrophotometry. The results have been interpreted in terms of solvent effects on the thermodynamic characteristics of complex formation and on complex–solvent interactions (the enthalpies of transfer of complex from poorly solvating medium to a given solvent).