From a eutectic mixture to a deep eutectic system via anion selection: Glutaric acid + tetraethylammonium halides

In pursuit of understanding structure–property relationships for the melting point depression binary eutectic mixtures, influence anion on solid–liquid (S–L) phase behavior was explored mixtures glutaric acid + tetraethylammonium chloride, bromide, and iodide. A detailed experimental evaluation S–L revealed that is shifted toward lower temperatures higher salt contents upon decreasing ionic radius. The fusion properties were experimentally inaccessible owing to thermal decomposition. data inter- extrapolated using various models Gibbs energy mixing fitted glutaric-acid rich side only, which allowed assessment point. Fitting a two-parameter Redlich–Kister expansion with Flory entropy, depth could be related radius anion. type, in particular its size, can therefore viewed as an important design parameter liquid window other salt-based deep solvents/systems.