Fragment Theory-based Ab Initio Evaluation of Intermolecular Interactions in Solution

Abstract

The intermolecular interaction networks formed in solution govern the progression of chemical reactions and the expression of macroscopic physicochemical properties. A quantitative understanding of these networks with fluctuations is essential for designing solution systems and predicting their functions. In this study, we proposed several fast and accurate methods to evaluate complex solute-solvent intermolecular interactions based on fragment theory rooted in quantum chemistry. Using representative systems—including ionic liquids, supercritical fluids, and aqueous osmolyte solutions—we assessed structural, thermodynamic, and kinetic properties based on the geometric and electronic features of their constituent molecules. Because the proposed approaches are free from empirical parameters, they offer broad applicability for the prediction of unknown chemical phenomena. This work presents a new strategy for advancing the physical chemistry of functional solvents.