On the Elusive Links between Solution Microstructure, Dynamics, and Solvation Thermodynamics: Demystifying the Path through a Bridge over Troubled Conjectures and Misinterpretations

Preferential Solvation Phenomena as Solute-Induced Structure-Making/Breaking Processes: Linking Thermodynamic Preferential Interaction Parameters to Fundamental Structure Making/Breaking Functions

“…In fact, at isobaric–isothermal conditions and infinite dilution of the i -solute in the ( j + k )-binary environment, we find according to Kirkwood–Buff fluctuation formalism that (see Appendix A for details) with where κ o denotes the isothermal compressibility of the ( j + k )-binary phase with its coefficient of diffusive stability D = ρ o /η o described by i.e., either in terms of the composition slopes of the activity coefficient of the j -solvent, or the inverse of a linear combination of fundamental structure making/breaking functions for the solvent–cosolvent intermolecular interactions.…”

“…Our goal here is to describe the fundamental relations between the microstructure of the ( j + k )-binary environment around any i -solute and the macroscopic (thermodynamic) responses without requiring knowledge of the intermolecular interactions in the system. In particular, we aim at describing explicitly and rigorously the solvation thermodynamics of the system in terms the corresponding fundamental structure making/breaking functions . − From a statistical mechanics viewpoint, these functions account for the average number of β-solvent molecules around the α-solute in either excess or deficit to that around any β-solvent, resulting from the underlying intermolecular asymmetry between the ββ-(solvent–solvent) and the αβ-(solute–solvent) interactions and allow the unambiguous microscopic interpretation of the solvation phenomena.…”