Photofading kinetics of pentaazadentate macrocyclic metal complexes

Pentaazadentate macrocyclic metal complexes are a kind of novel nonlinear o ptical materials with great potential applications in the photonics. The ph otofading kinetics of the complexes has been studied in different solvents by different visible radiations with different optical. intensities. The re sults indicate that the photofading processes obey the zero - order kinetic s for the reactant concentrations, which are affected only by the optical i ntensities and show a characterization of photochemical process. The photof ading rate constants are in the range of 1.2 x 10(-7) (in benzene) similar to 2.0 x 10(-5) h(-1) (in methanol) at visible wavelength greater than or e qual to 500 nm, and shorter visible wavelength may enhance the photofading rate constants. Electron - accepting groups, metal ions with large size and strong polar solvents can accelerate the photofading. However, the pentaaz adentate metal complexes studied still exhibit higher photostability.