AbstractVariation of the values of free energy of sorption of the methylene unit has been studied in the homologous series ofn‐alkyl methyl ketones,n‐alkyl butyl ketones,n‐alkyl acetates, and methyl esters of carboxylic acids, depending on the homologue number and the temperature of analysis. The experiment was carried out on a capillary column with a thick film of immobilized Silicone SE‐54 and on packed columns with OV‐210 and Silar‐10C. An intramolecular donor‐acceptor interaction between neighboring CH3 and CO groups is assumed to be the reason for anomalously high values of free energy of sorption of the first CH2unit in the series: RmC(O)OCH3, RmC(O)CH3, and RmC(O)C4H9. The anomaly disappeared in stationary phases containing strongly electronegative CF3and CN groups because of specific inter m