2021/09/01 by E. G. Tarakanova, V. D. Maiorov, В. Д. Майоров +2 · 1 citation
Chemical Engineering · Chemistry · #Analytical Chemistry and Chromatography #Chemical Thermodynamics and Molecular Structure #Thermodynamic properties of mixtures
paper · doi:10.1134/s0022476621090055
crossref issued 2021/09/01 · crossref published 2021/09/01 · crossref published-print 2021/09/01 · openalex publication_date 2021/09/01 · crossref published-online 2021/10/26 · crossref created 2021/10/26 · openalex created_date 2025/10/10 · crossref deposited 2026/03/26 · crossref indexed 2026/07/31 · openalex updated_date 2026/07/31
Abstract Structure, energy and spectral parameters of moieties of C3H7OH–HCl solutions with various compositions are calculated using density functional theory based on the regularities characterizing formation of complexes with hydrogen bonds in binary systems. It is shown that six concentration structural zones can be distinguished in the C3H7OH–HCl system (1:0-6:5). Liquid isopropyl alcohol consists of cyclic hexamers (C3H7OH)6. Solutions of each of the five subsequent zones contain two types of cyclic moieties whose average H-bond energies (~30-74 kcal/mol) are 5-10 times larger than those in hexamer (C3H7OH)6. The main interactions between components in the C3H7OH–HCl system occur inside such moieties (almost completely isolated from each other by alkyl groups of C3H7OH molecules). Such moieties contain previously unknown complexes with two quasi-symmetric bridges Cl⋯H⋯O and O⋯H⋯O, conjugated proton solvates, having one common oxygen atom. The concentrated solutions contain, in addition to conjugated proton solvates, moieties with the composition 2:2, each having four Cl⋯H⋯O bridges with similar parameters. The fact that the maximum density of these solutions and the HCl solubility limit approximately correspond to the component mole ratio 6:5 was explained and all features of obtained IR spectra were interpreted by using calculated data on the structure of C3H7OH–HCl solutions and that of observed complexes.