The melting behaviour of diamides of general formula (n - C pH 2p+1)CONH-(CH 2) qNHCO(n - C pH 2p+1) has been investigated by calorimetric, dilatometric and IR techniques. The conformational contribution to the melting entropy, calculated from the hypothesis of complete conformational freedom of the molecules at the melting point, has been compared with the experimental data. The higher melting points of the diamides, as compared with those of the linear hydrocarbons having the same number of conformationally flexible chain bonds, are attributed to a reduction of conformational freedom of the chain segments in the liquid state (caused by the large fraction of hydrogen bonds maintained in the melt).
Melting behaviour of a series of diamides / Carfagna, Cosimo; M., Vacatello; P., Corradini. - In: THERMOCHIMICA ACTA. - ISSN 0040-6031. - 28:(1979), pp. 265-275.
Melting behaviour of a series of diamides
CARFAGNA, COSIMO;
1979
Abstract
The melting behaviour of diamides of general formula (n - C pH 2p+1)CONH-(CH 2) qNHCO(n - C pH 2p+1) has been investigated by calorimetric, dilatometric and IR techniques. The conformational contribution to the melting entropy, calculated from the hypothesis of complete conformational freedom of the molecules at the melting point, has been compared with the experimental data. The higher melting points of the diamides, as compared with those of the linear hydrocarbons having the same number of conformationally flexible chain bonds, are attributed to a reduction of conformational freedom of the chain segments in the liquid state (caused by the large fraction of hydrogen bonds maintained in the melt).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
