H/D isotope substitution effect on the structural and thermodynamic parameters of intermolecular interaction in methanol at 278-318 K

The effect of H/D isotope substitution in methanol molecules on the geometr ical parameters of the latter and the energetics of particle interactions i s discussed in terms of scale particle theory and a model using internal pr essure as a measure of nonspecific interactions in liquids. Deuteration lea ds to reduced space occupied by a molecule irt the structural matrix of met hanol. It is established that isotopic substitution differentiates the dist ribution of specific and van der Waals interactions. The Sonnei are strengt hened and the latter weakened,when protium is substituted by deuterium in a group forming hydrogen bonds, and the case is opposite when deuterium is r eplaced in the methyl radical of methanol.