The influence of alkyl substituents on the chromatographic indicator of self-association ofN-containing heterocyclic compounds

The chromatographic indicator of the ability of substances to form associates in a pure liquid δT _b.p. proposed in our previous study was used to estimate the capacity for self-association of alkyl-substituted imidazoles, pyrazoles, pyrroles, oxazoles, isoxazoles, pyridazines, pyrimidines, pyrazines, and pyridines. Alkyl substituents introduced in heterocyclic compounds decrease the δT _b.p. values, which is consistent with the data on the heats of self-association of heterocyclic compounds in pure liquids. The reasons for the difference between the boiling point of a compound at standard pressure and its “gas-chromatographic boiling point” are discussed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp 319–322, February, 2000.