Preparation Of Hydroxy Deuteroporphyrin Derivates And Electrocatalysis

Metallo-porphyrins are found in most classes of organisms (chlorophyll, catalase, vitamin B12), including bacteria, fungi, plants, insects, and mammals. Metalloporphyrins have attracted much attention due to their special molecular structure and function, they have been hot areas of research such as photo-electron conversion, electrocatalysis, electroanalysis etc.. Metallo-deuteroporphyrin derivatives are more choser to cytochrome P-450in molecular strcture, so they should possess higher catalytic activity than tetraphenylporphyrin derivatives in theory when they are applied in bionic electron-catalysis. Thus, it is significantly meaningful to use metalloporphyrins as electrocatalyst.In this paper, we designed and synthesized a series of metallo-deuteroporphyrin derivatives and hydroxy-deuteroporphyrin functionalized graphene by covalent founctionalization. They are used as catalysts in the presence of oxygen and sodium nitrite. The detail contents of thesis are presented as follows:1. Firstly, Protoporphyrin dimethyl ester was prepared from hemin by a two-step reaction:demetalation and esterification. Iso-hematoporphyrin was systhsized by anti-Markovnikov addition; Hematoporphyrin dimethyl ester was prepared from hemin by a two-step reaction including HBr addition reaction and demetalation;2,7,12,18-tetramethyl-3,8-diethyl-13,17-di(3-hydroxyporpyl)porphyrin was systhesized by reduction of ester. Secondly,2,7,12,18-tetramethyl-13,17-di(3-hydroxyporpyl) porphyrin was prepared from hemin by a four-step including deferrization, demetalation, esterification and reduction. The optimum processes were obtained by optimized the experimental conditions, and the structures of products were confirmed by ultraviolet sprectrum, nuclear magnetism and mass spectrum.2. The corresponding metalloporphyrins were systhesized by reaction with different metal salts. The catalytic activity of these metalloporphyrins have been studied in reduction of dioxygen, and the catalytic mechanism has also been further studied. The results noted that metalloporphyrins have excellent electrocatalytic activity, among these metallo-porphyrins, cobalt-2,7,12,18-tetramethyl-3,8-diethyl-13,17-di(3-hydroxyporpyl)-porphyrin shows the best catalytic activities. Furthermore, we have discussed the influence of different metal ions and functional groups.3. A water-unsoluble porphyrin functionalized graphene has been synthesized by the reaction of graphene oxide and hydroxy porphyrin, and its structure was confirmed by ultraviolet sprectrum and infrared spectroscopy etc.. The catalytic activity of porphyrin functionalized graphene have been studied in the reduction of sodium nitrite, the mechanism of catalytic activity has been proposed and discussed. The results indicated that the porphyrin functional ized graphene modified GC electrode showed excellent electrocatalytic activity toward the reduction of sodium nitrite, resulting in highly sensitive amperometric biosensing with rapid response, wide linear range, low detection limit and good reproducibility.