光敏氧化还原反应——四苯基卟啉类化合物光敏还原甲基紫精

在DMSO-H₂O混合溶剂中,用TPP和它的四种金属络合物作为敏化剂,EDTA作为电子给体,经可见光照射,成功地还原了甲基紫精。反应活性顺序为ZnTPP>TPP>MgTPP》CoTPP>CuTPP。对以ZnTPP为敏化剂的反应,我们测得其量子产率为φ_418nm=0.08。我们考察了ZnTPP、MV²⁺和EDTA的浓度以及氧气对反应的影响。在一定浓度范围内,我们发现,反应速度与MV²⁺和EDTA浓度之间的关系符合于从推测的反应机理导出的动力学方程。

SENSITIZED PHOTO-REDOX REACTION-TETRAPHENYLPO-RPHIN AND METAL TETRAPHENYLPORPHINS INDUCED PHOTOREDUCTION OF METHYL VIOLOGEN

In DMSO-H₂O mixture, using TPP and metal TPP’s as sensitizers, EDTA as electron donor, methyl viologen was reduced to the blue methyl viologen cation radical upon irradiation with white light. Order of reactivity is as follows:ZnTPP > TPP > MgTPP≥≥CoTPP > CuTPPThe quantum yield of the ZnTPP sensitized reaction was determined to be 0.08, using potassium ferrioxalate as chemical actinometer. The effect of oxygen, the concentration dependency of sensitizer, methyl viologen and EDTA on the reaction rate, were also examined. The reduction of methyl viologen has been studied kinetically. With [EDTA]≥3×10^-4 M and [MV²⁺] between 1.0-10×10^-4 M, the reduction rate follows the following expression: where P is ZnTPP.