Solution calorimetry of organic nonelectrolytes as a tool for investigation of intermolecular interactions

Abstract

The paper is mainly the review and generalization of the previous publications of the authors. It demonstrates that solution calorimetry method gives the opportunities of more detailed understanding of various aspects of intermolecular interactions in solution. We are assured that prerequisite to such an understanding is the successive analysis of various solute–solvent systems from the simplest ones which include alkanes as a solute or as a solvent to the most complex systems with solvent self‐association via hydrogen bonding. Particular findings discussed in this paper are (i) an inconspicuous contribution of electrostatic solute–solvent interaction to the solvation enthalpy and, accordingly, the dominating contribution of dispersion interactions for nonspecifically solvated solutes; (ii) new, very general method for the extraction of specific interaction enthalpy from the enthalpy of solvation; (iii) new method of determination of self‐association enthalpies for the solvents associated via hydrogen bonding; (iv) new method for determination of cooperative hydrogen bonding enthalpies of proton acceptors with associated species of alcohols; (v) the unique method of experimental determination of the hydrophobic effect enthalpy. Copyright © 2007 John Wiley & Sons, Ltd.

Heats of Solution of Liquid Solutes in Various Solvents

“…Usually the errors of the heats of solution of alcohols in alkanes were up to ±(1-2) kJ mol −1 and for other solutions up to ±(0.1-0.3) kJ mol −1 . is range of errors of calculated heats of solution is in agreement with the precise data of direct calorimetric measurements [6][7][8][9][10][11]. Some conclusions can be made from the consideration of the obtained data on Δ soln (Dataset Item 1 (Table)).…”

“…From the analysis of the wide experimental data of the heats of solution and solvation of different solutes in the medium of cycloalkanes, very interesting and useful relation was observed [10]. e value of enthalpy of solvation (Δ solv A/ -hexane /kJ mol −1 ) can be predicted from the highreliable (4) [10]:…”

“…e value of enthalpy of solvation (Δ solv A/ -hexane /kJ mol −1 ) can be predicted from the highreliable (4) [10]:…”

“…In the case of ideal solution, there is a complete compensation of breaking and forming energy in (1) with zero value of Δ soln A S . In overwhelming majority of measurements, the values of the heat of solution differ from zero and supply with the additional information for analysis of the nature of these steps [10,11].…”

“…At the present, there are a lot of data on the heats of mixing of binary liquid systems [1][2][3][4][5] and considerably less data on the heats of solution from direct calorimetric measurements [6][7][8][9][10][11]. In two handbooks [1,2] about 2500 tables of data on the heats of mixing (Δ mix ) of the different liquid solutes in organic and inorganic solvents have been collected, whence the values of the enthalpies of solution were calculated.…”