Quantum chemical perspective of efficient NLO materials based on dipolar trans-tetraammineruthenium (II) complexes with pyridinium and thiocyanate ligands: First theoretical framework

In this research work non-linear optical (NLO) properties of dipolar trans-tetraammineruthenium (II) complexes with pyridinium and thiocyanate ligands have been calculated by using density functional theory (DFT). For reference systems, four functionals B3LYP, PBE0, BHandHLYP and CAM-B3LYP were employed to select the best functional to study designed compounds on the basis of similarity between calculated and experimental results. The calculated static hyperpolarizabilities were found to be strongly functional dependent. The results from CAM-B3LYP seem to be more reliable when compared to the available experimental data. Thus, new compounds have been theoretically designed by the substitution of electron withdrawing atom/groups as acceptor on reference systems. All the designed compounds display intense band due to metal-to-ligand charge transfer (MLCT). The second-order polarizability has shown a remarkable increase on substitution of strong electron withdrawing atom/groups as an acceptor. The second-order polarizability of all the designed systems was high calculated to be 185 × 10−30 to 842 × 10−30 esu.