Vasiltsova Tatiana, Heintz Andreas
Department of Physical Chemistry, University of Rostock, Hermannstrasse 14, D-18051, Rostock, Germany.
Phys Chem Chem Phys. 2007 Dec 21;9(47):6203-13. doi: 10.1039/b712902e. Epub 2007 Oct 19.
A recently developed statistical mechanical model for calculating Kirkwood correlation factors gK in self associating liquids and liquid mixtures has been applied for the simultaneous description of gK, the molar enthalpy of mixing HEM and the infrared absorption of monomer alcoholic species as function of the composition in alkanol + hexane and alkanol + pentane mixtures (alkanol: butan-1-ol, pentan-1-ol, hexan-1-ol, heptan-1-ol, sec-butanol, tert-butanol). The majority of parameters involved into the theory are obtained by independent quantum mechanical ab initio calculations of molecular clusters consisting of up to four alcohol molecules. As a consequence only two parameters have to be adjusted freely to each binary system, a third parameter responsible for the non specific intermolecular dispersion interaction has been adjusted within a limited range of possible values given by physical arguments. Excellent agreement between theory and experimental data of gK, HEM and IR absorbance is obtained covering the whole range of concentration including the temperature dependence of these properties without adjusting further parameters. The Kirkwood correlation factor gK turns out to be a sensitive response to peculiarities of the molecular structure of hydrogen bonded systems in the condensed liquid state. The successful application of the theoretical model opens a new way of a deeper and more reliable understanding of such liquid structures.
