Dissoluts

Dissoluts are discrete, solvated fragments that retain identifiable molecular identity within a solution. They are proposed as stable, solute-like units embedded in the solvent, distinguished from bulk solvation by persistent spectral or kinetic signatures.

The term is used mainly in discussions of non-ideal dissolution in complex media, such as ionic liquids, deep eutectic solvents, or highly structured polymer and biomolecule systems.

Formation and properties: Dissoluts arise when specific solvent–solute interactions create transient clusters that remain resolvable on experimental timescales. They exchange with the surrounding solvent slowly enough to show characteristic features in spectroscopy, but fast enough to avoid permanent precipitation. Detection methods include NMR, UV–visible spectroscopy, infrared spectroscopy, and time-resolved techniques; computational models are often employed to estimate lifetimes.

Examples and relevance: Reported in some studies of metal salts in ionic liquids and certain polymers, though evidence remains debated. If validated, the dissolut concept could refine understanding of solubility limits, dissolution pathways, and controlled release in materials processing and pharmaceutical contexts.

Status and critique: The concept is controversial; some researchers view dissoluts as a useful heuristic for complex solvation, while others regard them as artefacts of measurement or misinterpretation of fast exchange processes. More research is needed.