Thermal dissociation of supramolecular complexes on the basis of 18-crown-6 and amino acids

The possibility of isolation of crystalline supramolecular complexes of 18-crown-6 with glycine, L-alanine, L-valine, L-leucine, L-phenylalanine, L-proline, L-hystidine, and L-threonine from aqueous solutions was studied. Comparative analysis of thermal decomposition of the complexes and their individual components and mechanical mixture was studied by means of thermogravimetry, differential thermal analysis, and differential scanning calorimetry. Crystaline complexes of 18-crown-6 with glycine, L-alanine, and L-hystidine were isolated and shown to be stable up to 140°C, which was additionally confirmed by IR spectroscopy.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 8, 2004, pp. 1313–1317.Original Russian Text Copyright © 2004 by Terekhova, Kulikov, Barannikov.This revised version was published online in April 2005 with a corrected cover date.