The influence of isomerism on the enthalpies of solution of dipyrrolylmethanes

Abstract

The enthalpies of solution of 3,3′,4,4′-tetramethyl-5,5′-dicarbethoxydipyrrolylmethane-2,2′ and its α,β-and β,β isomers in organic solvents of various natures were measured calorimetrically at 298.15 K. The enthalpies of transfer of the compounds from benzene into chloroform, pyridine, dimethylsulfoxide, and dimethylformamide were calculated. Pyridine, dimethylsulfoxide, and formamide (proton acceptor solvents) specifically solvated the NH groups of dipyrrolylmethanes. Solvation interactions could be sterically complicated depending on the type of the isomer.