solvated

Solvated describes a species that is dissolved in a solvent with solvent molecules arranged around it. Solvated species include ions, neutral molecules, or even electrons that are stabilized by interactions with solvent molecules. The immediate assembly of solvent molecules around the solute is called the solvation shell, which can extend over several layers and is often dynamic.

Solvation arises from electrostatic interactions between the solute and solvent dipoles, hydrogen bonding, and van der Waals forces. The strength and structure of solvation depend on the solvent’s polarity, dielectric constant, and ability to hydrogen-bond. Highly polar or protic solvents, such as water, strongly stabilize charged or polar solutes, while nonpolar solvents provide weaker stabilization.

Solvation can be described explicitly, by modeling individual solvent molecules around the solute (explicit solvation), or implicitly, by treating the solvent as a continuous dielectric medium (implicit solvation). In many contexts, the solute in solution is surrounded by a first solvation shell that exchanges on picosecond to nanosecond timescales, reflecting the dynamic nature of the solvent environment.

Examples and implications: a solvated ion in water benefits from hydration shells that lower its energy and influence its reactivity; a solvated electron in water is stabilized by the polar solvent. Solvation affects reaction kinetics, spectroscopic properties, and electrochemical behavior. Computational approaches range from molecular dynamics with explicit solvents to continuum models that estimate solvation energies, enabling insights into solvation structure and thermodynamics.