Synthesis Of Metallo-mesoporphyrin Derivatives Bearing Disulfide Bond For The Electrocatalytic Reduction Of Oxygen

Metalloporphyrin widely exists in the nature, with higher conjugated structure and chemical stability, it has broad application prospects in photo-electron conversion, analytical chemistry, electrocatalytic etc. Now mesoporphyrin has become the preferred model compound in porphyrin bionic applied research since it is more similar to natural porphyrin, and having strong stability than tetraphenylphyrin, protophyrin etc. Metallo-mesoporphyrin applied to the electrocatalytic reduction of oxygen could drive the further application of metallo-porphyrin in the electro-catalytic and electrochemical sensors significantly.In the paper, mesoporphyrin was prepared from hemin, then a series of metallo-mesoporphyrin derivatives bearing disulfide bond were synthesized through modifying13,17-groups of mesoporphyrin. Based on the catalytic ability of porphyrin, all the substances were used in electrocatalytic reduction research of dissolved oxygen by self-assembled to gold electrodes. The contents of this thesis are presented as follows:(1) Mesoporphyrin was prepared from hemin through two different routes, then a series of cystine ester mesoporphyrin derivatives were synthesized by condensation with different esterified L-cystine, finally, the corresponding cystine ester cobalt(Ⅱ) mesoporphyrin derivatives were got by reaction with metal cobalt salts. In addition, the optimum reaction condations were obtained by optimizing the experimental conditions, and the structures of productions were confirmed by1H NMR, IR, MS, UV-Vis.(2) Through the covalent bond of S-Au, all the metal lo-porphyrin derivatives from (1) were self-assembled to gold electrodes, the modified electrodes were characterized by X-ray and electrochemical method (CV). The results showed that all the target products could oriently and stably assembled onto the surface of gold electrodes, and the electrocatalytic ability of cystine dimethyl ester cobalt(Ⅱ) mesoporphyrin is better than cystine dimethyl ester cobalt(Ⅱ) deuteroporphyrin.(3) The assembled modified electrodes from (2) were used in electrocatalytic reduction of dissolved oxygen. The investigation results showed that they have good electrocatalytic ability to the reduction of dissolved oxygen which could be reduced by the4electrons reaction to HbO; the electrocatalytic reduction ability to the dissolved oxygen of cystine dimethyl ester cobalt(Ⅱ) mesoporphyrin, cystine diethyl ester cobalt(Ⅱ) mesoporphyrin, cystine dipropyl ester cobalt(Ⅱ) mesoporphyrin and cystine dibutyl ester cobalt(Ⅱ) mesoporphyrin got better because of the better electronic effects of different esterifying groups.