Effect of anion and methylation on the interionic interactions and reactivity of 1-butyl-2,3-dimethyl imidazolium-based ionic liquids

Abstract

The study presents the investigation of anion and methylation effects on the interionic interactions, thus explaining the variations in the reactivity, electronic, and spectroscopic features in 1-butyl-2,3-dimethyl imidazolium-based ionic liquids with chloride, tetrafluoroborate, and hexafluorophosphate anions. Ground state electronic structures, IR and Raman spectra, electronic transition characteristics, and chemical shifts of the ionic liquids were obtained using DFT calculations at the B3LYP/6–311++G(d,p) level of theory. The calculated electron densities were analyzed to determine intra- and interionic interactions at critical points using Reduced Density Gradient and topological analysis through the atoms-in-molecules approach. Experimental spectroscopic characterizations were performed using the FT-IR, FT-Raman, NMR, and UV–vis techniques. These techniques and DFT calculations provide essential contributions to interpreting spectral features concerning the structure and dynamics of ionic liquids. Furthermore, molecular docking studies were performed to determine the binding status of studied ionic liquids with human serum albumin to explore their activity, thus reporting their potential due to their demand in pharmacology.