Nonlinear optical properties, structural and transition state analyses of ionic liquids: DFT and DFT-D2/D3 studies

Abstract

This paper includes the structural properties, transition state analysis and NLO properties of the ionic liquids in quantum chemical calculations. Hydrogen bond geometries calculated by B3LYP and ωB97XD approaches have been compared with the crystallographic data in the literature. Transition state analysis have been carried out using Synchronous Transit-Guided Quasi-Newton (STQN) method with QST2 option and Density Functional Theory. Forms according to the positions of the proton on hydrogen bond axes and transition states have been evaluated by relative energy scanning. Interactions between anions and cations in ionic liquids optimizations have been studied by CP approach with D2 and D3 versions of Grimme’s dispersion correction. Electric dipole moments, dipole polarizability, first and second dipole hyper polarizability and important components have been calculated, statically and dynamically for ionic liquids. Effective and stable structures in terms of NLO have been evaluated. In addition, B3LYP and ωB97XD functionals approaches have been tested considering Grimme’s D2/D3 dispersion models for lithium interactions with bis(trifluoromethanesulfonyl)amide and methylsulfonate anions.