Iridium(III) complexes in discs for two-photon excitation applications

Abstract

Ir(ppy)2(H2dcbpy)PF6 (IrHP, ppy=2-phenylpyridine, H2dcbpy=4,4′-dicarboxy-2,2′-bipyridine) as the bridging ligand mixed with Zn(NO3)2·6H2O in a ratio of 1:2 (ZnIrHP) in PMMA discs has been synthesized. The two-photon excitation emission of IrHP and ZnIrHP is ascribed to a 3MLCT transition. The two-photon absorption (2PA) cross section and two-photon induced excited state absorption (ESA) cross section of IrHP were deduced as 1.37×104±6.87×102GM and 6.63×10−22±3.31×10−23cm2, respectively, at 800nm (1GM=10−50cm4s/photon). In contrast, the 2PA of ZnIrHP exhibits higher-order nonlinearity and the cross section was 5.68×105±2.84×104GM.