Substituted tetra-2,3-pyrazinoporphyrazinino copper(II) complexes: synthesis and nonlinear optical refractive and absorptive properties

Tetra-substituted tetra-2,3-[5,6-(9,10-phenanthro)pyrazino]porphyrazinino copper(II) complexes (AzaPhc, 5a–d) have been prepared via complexation of mono-substituted 5,6- (9,10-phenanthro)-2,3-dicyanopyrazines with copper(I) chloride. Their nonlinear optical properties have been studied by the Z-scan measurements at 532 nm. We found that their effective nonlinear refractive indices n2eff (ranging from −4.6×10−10 to −10.0×10−10 e.s.u.) are about two to four times larger than the octa-substituted phthalocyaninine complex, and their triplet excited-state absorption cross sections σexτ (ranging from 8.2×10−19 to 9.8×10−19 cm2) are about an order less than the phthalocyanine compound. The one-photon excitation and the heating effect have been applied to interpret our experimental results.