Tuning the dipolar second-order nonlinear optical properties of 5-pi-delocalized-donor-1,3-di(2-pyridyl) benzenes, related cyclometallated platinum(II) complexes and methylated salts

The synthesis and characterization of three 5-p-delocalized-donor-1,3-di(2-pyridyl) benzenes is reported along with that of their related cyclometallated platinum(II) complexes and N, N-dimethylated iodide salts. The second-order nonlinear optical (NLO) properties of all the compounds have been determined by the Electric Field Induced Second Harmonic generation technique, showing how the mu beta(EFISH) absolute value of 1,3-di(2-pyridyl) benzenes can be tuned by the nature of the substituent on position 5 of the central benzene ring, and greatly increased by cyclometallation to Pt or by N-methylation.