The microscopic structure and hydrogen bonding interactions between 1- acetoxymethyl-3-methylimidazolium tetrafluoroborate and DMSO

Abstract Ester-functionalized ionic liquids (ILs) are widely applied in electrochemistry, separation, reduction and extraction, but there are few basic researches on them. This study investigates the hydrogen bonding interaction between the ester-functionalized ILs and DMSO, as well as compares it to the ethyl acetate − DMSO (CH3COOCH2CH3 − DMSO) system. Experimental and quantum chemical calculation sections were employed for this purpose. The results demonstrate that: (1) The hydrogen bonding interactions in the 1-acetoxymethyl-3-methylimidazolium tetrafluoroborate (AOMMIMBF4 − DMSO) and 1-acetoxyethyl-3-methylimidazolium tetrafluoroborate (AOEMIMBF4 − DMSO) systems are stronger than that in CH3COOCH2CH3 − DMSO system. (2) AOMMIMBF4 − DMSO and AOEMIMBF4 − DMSO systems showed comparable interactions. (3) The complexes were identified by the excess spectra and quantum chemical calculations, which are 2AOMMIMBF4, 2AOMMIMBF4 − DMSO, AOMMIMBF4 − DMSO and [AOMMIM]+−DMSO complexes, respectively. This study provides further insights into the hydrogen bonding interactions between ester-functionalized IL and DMSO, which is make for further applications of ester-functionalized ILs.