Gas chromatographic determination of the free energy of sorption of methylene units ofN-alkylsubstituted six-membered cyclic amines

The free energy of sorption of methylene units, G(CH₂), for the homologous series ofN-alkylsubstituted morpholines, thiomorpholines, piperidines and 2-methyl-, 3-methyl-, 4-methyl- and 2,6-dimethylpiperidines was determined. It was shown that the dependence of these values on the number of CH₂ units in the carbon chain is not linear. Universal equations for calculating the values of the energy contribution depending on the number of CH₂ units in the carbon chain were obtained. Abnormally high values of free energy of sorption of the first CH₂ unit were found in all series studied and reasons for the anomaly are discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 437–439, March, 1994.This work was made possible by the financial support of Russian Foundation for Basic Research, project No. 93-03-4969,