Probing the thermodynamic properties of polyol deep eutectic solvents: Based on electrostatic potential polarization and inverse gas chromatography

• Electrostatic potential extremes guide deep eutectic solvent-solute interaction analysis. • Inverse gas chromatography measures thermodynamic properties of choline chloride-polyol DESs. • Selectivity/capacity benchmarked via cyclohexane/benzene, cyclohexane/ethanol, benzene/methanol separations. This study innovatively combines molecular electrostatic potential (ESP) analysis with inverse gas chromatography (IGC) to systematically probe the thermodynamic behavior of polyol deep eutectic solvents (DESs), offering a dual-methodology framework for green solvent design in complex industrial separations. By integrating quantum chemical polarity mapping of three DESs with temperature-dependent interaction measurements across 41 solute probes, we establish a critical correlation between functional group polarity and hydrogen-bonding capacity. The ESP analysis uniquely reveals that the interaction strength order follows: alcohols > ketones > ethers > esters > halocarbons > aromatics > alkanes, directly linking molecular polarization effects to separation selectivity. Through precise IGC determination of infinite dilution activity coefficients (303.15–343.15 K), we demonstrate thermally responsive solvent–solute interactions, where 85 % of tested systems exhibit decreasing affinity with rising temperature. Notably, the DESs achieve superior selectivity and capacity in benzene-methanol separation compared to conventional ionic liquids and existing DES benchmarks, validating their potential as sustainable alternatives. This work provides a novel paradigm for rational DES screening through coupled computational-experimental analysis, advancing the mechanistic understanding of hydrogen-bond-driven separations.