Syntheses, characterization and third-order nonlinear optical properties of ruthenium(II) complexes containing 2-phenylimidazo-[4,5-f][1,10]phenanthroline and extended diimine ligands

Four novel ruthenium(II) complexes [RU(PIP)(2)L](2+) [PIP= 2-phenylimidazo- [4,5-f][1, 10]phenanthroline, L = 1, 10-phenanthroline (phen), 1,4,8,9-tetr a-aza-triphenylene (tatp), dipyrido[3,2-a:2',3'-C]phenazine (dppz) and benz o[i]dipyrido[3,2-a:2',3'c]phenazine (dppn)] have been synthesized and chara cterized. The electrochemical behaviors of these complexes have been studie d in acetonitrile by cyclic voltammetry. The nonlinear optical properties o f the ruthenium(II) complexes were investigated by Z-scan techniques with 1 2 ns laser pulses at 540 nm, and all of them exhibit both NLO absorption an d self-defocusing effect. The corresponding effective NLO susceptibility \c hi (3)\ of the complexes is in the range of 4.78-8.49 x 10(-12) esu. The re sults indicate that the extension of the pi -framework of the ligands has a n effect on the NLO properties of the complexes. (C) 2001 Elsevier Science Ltd. All rights reserved.