水溶性卟啉催化氧化1,5-萘二酚

合成并表征了系列水溶性卟啉配体[H2TPPS: 5,10,15,20-四-(4-磺酸基苯基)-21H,23H-卟啉, H2TMPyP: 5,10,15,20-四(4-吡啶基)-21H,23H-卟啉, H2TCPP: 5,10,15,20-四-(4-羧基苯基)-21H,23H-卟啉]及相应的铁、锌及钴配合物. 将水溶性卟啉作为光敏剂, 用于1,5-萘二酚的光催化反应, 产物为5-羟基-1,4萘醌. 利用UV-Vis方法对卟啉催化1,5-萘二酚的反应过程进行了监测, 探索了水相和水/二氯甲烷双相催化体系, 确定了较为理想的反应条件. 探讨了不同取代基和不同金属离子对卟啉催化性能的影响, 初步讨论了催化机理. 结果表明, 具有磺酸根阴离子取代基的水溶性卟啉具有最好的催化活性; 卟啉的催化活性与其在反应体系中的稳定性密切相关; 铁卟啉在反应初期呈现很高的催化活性, 但在光照条件下容易发生光解而导致催化活性的降低; 无金属的磺酸卟啉在催化体系中的催化活性和稳定性最好.

Catalysis of Water-soluble Porphyrins for Oxidation of 1,5-Dihydroxynaphthalene

A series of water-soluble free base porphyrins(H2TPPS, H2TCPP and H2TMPyP) and their metal complexes(FeTPPS, ZnTPPS, CoTPPS) were efficiently synthesized and characterized. As photosensitizers, these porphyrins were used to catalyze the oxidation of 1,5-dihydroxynaphthalene under visible light irradiation. The main product were identified as 1,5-dihydroxynaphthalene. The catalytic process was monitored by UV-Vis method and the optical catalytic conditions were established. The water phase system and water-dichloromethane double phase system were explored. The effects of various factors such as substituent groups, central metal ions were investigated. The catalytic results show that anionic porphyrins have efficient catalytic activity; At the beginning of the reaction, high catalytic acitivity can be obtained for iron porphyrin, while it decreases greatly because of catalyst photolysis; The sodium sulfonic porphyrin is the most stable catalyst in the reaction system and has the best catalytic activity.