Study On Preparation And Properties Of Compounds Based On Metal Porphyrin Derivatives

Porphyrins and their metal derivatives having unique photoelectric properties are high performance photosensitizer,can efficiently absorb visible light and convert energy to oxygen generating active oxygen for catalyzing substrates.They have been developed as photocatalysts for photocatalytic degradation of pollutants,especially organic pollutants self-degraded difficultly in water.However,most porphyrins and their metal derivatives are hydrophobic and easily self-aggregate,resulting in reduced photocatalytic efficiency,and water-soluble porphyrins have problems such as non-recyclability,secondary pollution,etc.Combining metal porphyrins with functional polymers via their easily modified properties is an effective strategy to solve the above problems,especially with water-soluble environmentally responsive functional polymers.Firstly,5,10,15,20-tetra?4-p-hydroxyphenyl?-21H,23H-zincporphyrin?ZnTHPP?was synthesized in the thesis,and four zinc-porphyrin initiators with 1 to 4 initiator groups respectively were synthesized via the controlled esterification with 2-bromoisobutyryl bromide.Then,zinc-porphyrin based multi-arm star Poly?N-isopropylacrylamide??ZnTHPP-?PNIPAM-Br?n?with n=1,2,3 and 4 arms were successfully prepared via ATRP polymerization initiated by the four zinc-porphyrin.All four polymerizations have good water solubility and temperature sensitivity,their LCST is between 29.5?-31.5?.Photocatalytic performance was tested with rhodamine B aqueous as substrate,it was found as the number of arms increased,the photocatalytic activity and stability of the star polymer increased.The four-arm star polymer ZnTHPP-?PNIPAM-Br?₄ was shown the best photocatalytic performance and stability,could be recycled by warming.In the other hand,the metal porphyrins occupy a relatively small proportion in four-arm star polymers,leading to low catalytic activity and cannot meet some practical needs.In order to solve this problem,5-?4-propargyloxyphenyl?-10,15,20-triphenylzinc-21H,23H-porphyrin?ZnTPP-Py?was synthesized,and star-shaped poly?N-isopropylacrylamide?with zinc-porphyrin as the core and N₃ as the end groups?ZnTHPP-?PNIPAM-N₃?₄?was obtained.Finally,a novel star-shaped poly?N-isopropylacrylamide?with two zinc porphyrins as the core and end groups respectively?ZnTHPP-?PNIPAM-Zn TPP?₄?was prepared via click reaction.This strategy effectively solves the problem of low porphyrin content in polymers and also shows better photocatalytic performance.In addition,the active oxygen capture agents were used to detect the presence of possible active oxygen in the photocatalytic process,and the photocatalytic mechanism of ZnTHPP-?PNIPAM-ZnTPP?₄ in the degradation of RhB dyes was explored.