Molecular interactions in 2-hydroxyethyl-trimethylammonium acetate (choline acetate) ion pair

The molecular structure, electron density topography, vibrational frequencies and molecular interactions of the choline acetate ion pair were investigated using M05-2X based density functional approach. Different conformers of choline acetate ion pair based on molecular interactions were obtained in the gas phase and also in a solvent environment. The lowest energy conformer showed the presence of both O–H···O and C–H···O interactions. A strong binding between the cation and anion was observed in the lowest energy conformers through ion pairing free energies. The O–H···O and C–H···O interactions were weakened from the gas phase to the condensed phase.

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