The substituent group activity in the anion of cholinium carboxylate ionic liquids on thermo-physical, chemical reactivity, and biological properties: A DFT study

The thermo-physical, chemical reactivity and biological interaction of cholinium cation Ionic Liquids (ILs) were investigated as theoretical by density functional theory (DFT). Some thermo-physical parameters such as free energy, entropy, dipole moment, binding energy, nuclear energy, electronics energy, the heat of formation were computed. The chemical reactivity of molecule like highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), HOMO-LUMO gap, ionization potential, electronegativity, hardness, softness and electron affinity were calculated. Properties like charge density, surface area grid, volume, LogP, polarizability, refractivity, and molecular mass were calculated using the quantitative structure activity relationship (QSAR). The cholinium benzoate (IL01), cholinium-2-nitro-benzoate (IL02), cholinium-2-methylbenzoate (IL03), cholinium -2-hydroxy benzoate (IL04), cholinium -2-chlorobenzoate (IL05), and cholinium -2-flurobenzoate (IL06) were taken for study. With adding of substituent groups to the anion, the chemical stabilit increased, and chemical reactivity decreased in the order of -H > -CH3 > -OH > -Cl > F- > -NO 2 groups. The physical properties and biological activity are observed to be changed irregularly for different substituent groups.