Complexation reactions in pyridine and 2, 6-dimethylpyridine-water system: The quantum-chemical description and the path to liquid phase separation Academic Article uri icon

abstract

  • Phase separation in substituted pyridines in water is usually described as an interplay between temperature-driven breakage of hydrogen bonds and the associating interaction of the van der Waals force. In previous quantum-chemical studies, the strength of hydrogen bonding between one water and one pyridine molecules (the 1: 1 complex) was assigned a pivotal role. It was accepted that the disassembly of the 1: 1 complex at a critical temperature leads to phase separation and formation of the miscibility gap. Yet, for over two decades, notable empirical data and theoretical arguments were presented against that view, thus revealing the need in a revised quantum-mechanical description. In the present study, pyridine-water and 2, 6-dimethylpyridine-water systems at different complexation stages are calculated using high level Kohn-Sham theory. The hydrophobic-hydrophilic properties …

publication date

  • March 14, 2018