THE HEATS OF SUBLIMATION OF DISPERSE DYES

Abstract

The heats of sublimation of disperse dyes have been derived from the data obtained by Knudsen effusion method and Knudsen torque effusion method, and the following results have been obtained.1. The values of heats of sublimation obtained by the two methods are essentially identical in the range of experimental error.2. The measure of precision in the value by Knudsen torque effusion method is higher than that in the value by Knudsen effusion method.The values of the heats of sublimation by Knudsen torque effusion method shown the high measure of precision are discussed in terms of the molecular structure, and the following results have been obtained.1. The energy of inter-molecular hydrogen bond based on a free hydrogen atom attached to nitrogen of 1-amino, 2-amino, 1:2-diamino and 1-amino-4-hydroxy anthraquinones is 2-4Kcal/mol.2. The energy of inter-molecular hydrogen bond based on 4′-amino and 4′-hydroxy group attached to 2:4-dinitrodiphenylamine is 2 Kcal/mol respectively.3. The energy of dipole-dipole interaction based on the nitro group of 1-nitroanthraquinone, 2-nitro, 4-nitro and 2:4-dinitrodiphenylamine is 5.1, 2.5, 7.8 and 13.7Kcal/mol respectively.