New task-specific ionic liquids based on phenyl diazenyl methyl pyridinium cation: Energetic, electronic and optical properties exploration based on DFT calculations.

Physicochemical properties of the three series of task-specific ILs formed from methyl pyridinium [MPy]+, phenyl diazenyl methyl pyridinium [DMPy]+ and functionalized diazenyl methyl pyridinium [X-DMPy]+ (X: NH2, OH, OCH3, CH3, C2H5, H, F, CHO, CN and NO2) cations and benzoate ([Y1]-), benzenesulfonate ([Y2]-), nitrate ([Y3]-) and tetra fluoroborate ([Y4]-) anions were investigated using density functional theory (DFT) calculations at M06-2X/AUG-cc-pVDZ level of theory. For the introduced task-specific ILs the structural parameters, energetic, electronic and topological characteristics were calculated and discussed using electrostatic maps and indexes of NBO, QTAIM, ECW and NCI. The effect of the type of anions, functional group, variation of the substituents on the functional group at cationic part on the interaction energy as well as some of their physical, chemical and optical properties are taking into account.