Spontaneous liquifaction of isomerizable molecular crystals
Authors: Tombari E., Ferrari C., Salvetti G., Johari G.P.
Autors Affiliation: Istituto per i Processi Chimico-Fisici del CNR, 56124 Pisa, Italy; Department of Materials Science and Engineering, McMaster University, Hamilton, Ont. L8S 4L7, Canada
Abstract: A lattice vacancy raises the energy of the neighboring (flexible) molecule in a crystal, which may be enough to isomerize it to a tautomer that does not fit the lattice site, thus creating a liquidlike local region embedding the vacancy. Similar regions may appear elsewhere in the lattice and the regions may ultimately merge. Thus a crystal may spontaneously liquefy over a period of hours to years at a temperature below its normal melting point. Simultaneous heat capacity and heat absorption measurements of several such molecular crystals show that they spontaneously liquefy at a temperature far below their reputed melting point, according to a non-exponential rate kinetics and a temperature dependent rate constant, and do not crystallize on cooling.
Journal/Review: JOURNAL OF CHEMICAL PHYSICS
Volume: 126 (2) Pages from: 021107-1 to: 021107-4
KeyWords: MAGNETIC-RESONANCE SPECTROSCOPY; BETA-D-FRUCTOSE; LIQUIDSDOI: 10.1063/1.2432345Citations: 17data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2023-05-28References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here