Synthesis, Characterization And Photocatalytic Degradation Properties For 1,5-dihydroxynaphthalene Of Water-soluble Phenyl Porphyrins

Porphyrins are active centers of many natural proteins and enzyme and play a great role in the life activities. Water-soluble porphyrins and metal porphyrins can degrade phenol and naphthol as photocatalyst in the water phase. (PAMAM) dendrimers are three-dimensional ellipsoid tree macromolecules with precise molecular structure and geometric symmetry of high degree, and is very important to controlled release of porphyrin drugs.A series of water-soluble free base porphyrins (H₂TPPS, H2TCPP,H2TMPyP,TDCPP and H₂TPPSCl₃) and their metal complexes (FeTPPS, ZnTPPS, CoTPPS) have been efficiently synthesized by Adler method and characterized by Uv-vis, CD, and NMR.As photosensitizer, these porphyrins have been used to catalyze the photodegradation of 1,5-dihydroxynaphthalene under visible light irradiation. The main product has been identified as 1,5-dihydroxynaphthalene. The catalytic process has been monitored by Uv-vis method and the optical catalytic conditions have been established. The water phase system and water-dichloromethane double phase system have been explored. The effects of various factors such as substituent groups, central metal ions have been investigated in detail. The catalytic results show that anionic porphyrins whose substituents are with high dissociation degree have efficient catalytic activity; At the beginning of the reaction, high catalytic activity can be obtained for iron porphyrin, while it decreases greatly because of catalytic photolysis; The sodium sulfonic porphyrin is the most stable catalyst in the reaction system and has the best catalytic activity.The interactions between H₂TPPS, FeTPPS respectively with G2 PAMAM dendrimer were investigated. And the binding numbers and equilibrium constants have been calculated according to host-guest principle. The results show that for H₂TPPS, some SO₃^- can be coordinated; for FeTPPS, the coordination ability significantly enhanced after H₂TPPS coordinated with Fe³⁺.The effects of photocatalytic properties of porphyrin have been investigated after H₂TPPS, FeTPPS respectively formed new water-soluble systems with G2 PAMAM dendrimer. The results show that the new system can effectively improve the stability of porphyrin.