Abstract
We review the fundamentals underlying a general molecular-based formalism for the
microscopic interpretation of the solvation phenomena involving sparingly soluble solutes in
compressible media, an approach that hinges around the unambiguous splitting of the species
correlation function integrals into short-(finite) and long-ranged (diverging) contributions at
infinite dilution, where this condition is taken as the reference system for the derivation of
composition expansions. Then, we invoke the formalism (a) to illustrate the well-behaved nature
of the solvation contributions to the mechanical partial molecular properties of solutes at infinite
dilution, (b) to guide the development of, and provide molecular-based support to, the
macroscopic modeling of high-temperature dilute aqueous-electrolyte solutions, (c) to study
solvation effects on the kinetic rate constants of reactions in near-critical solvents in an attempt
to understand from a microscopic perspective the macroscopic evidence regarding the
thermodynamic pressure effects, and (d) to interpret the microscopic mechanism behind
synergistic solvation effects involving either co-solutes or co-solvents, and provide a molecular
argument on the unsuitability of the van der Waals one-fluid (vdW-1f) mixing rules for the
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description of weakly attractive solutes in compressible solvents. Finally, we develop
thermodynamically consistent perturbation expansions, around the infinite dilution reference, for
the species residual properties in binary and ternary mixtures, and discuss the theoretical and
modeling implications behind ad hoc first-order truncated expansions.