Electronic absorption spectra and nonlinear optical properties of ruthenium acetylide complexes: a DFT study toward the designing of new high NLO response compounds.

In this study we have used density functional theory (DFT) to calculate nonlinear optical properties and simulate the UV-VIS absorption spectra of ruthenium acetylide complexes.Among the studied systems, system 4 has shown highest non-linear optical properties (a = 72.92 × 10(-24)esu and b = 76.32 × 10(-30)esu).New compounds have been theoretically designed by the extension of conjugation length and substitution of electron withdrawing atom/groups as acceptor on system 4. All designed compounds show intense band due to metal-to-ligand charge transfer (MLCT).Second-order polarizabilityof new design compounds was remarkablyhigh as compared to system 4 (123.35 × 10(-30)to 360.23 × 10(-30)esu). Effect of acceptors was more prominent than pi-spacers. Results of theoretical investigation indicate that all systems should be excellent non-linear optical materials.