TR-ESR Investigation on Reaction of Vitamin C with Excited Triplet of 9,10-phenanthrenequinone in Reversed Micelle Solutions  

维生素C对菲醌三重激发态的淬灭机理及动力学研究

作　　者：许新胜[1] 史蕾[1] 刘毅[1] 季学韩[1] 崔执凤[1] 

机构地区：[1]安徽师范大学原子与分子物理研究所,芜湖241000

出　　处：《Chinese Journal of Chemical Physics》2011年第2期150-154,I0003,共6页化学物理学报（英文）

基　　金：ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20903004） and the Science Foundation of the Education Committee of Anhui Province （No.J2010A145）. We are grateful to professor Li-min Zhang for his help in transient absorptive spectrum measurement.

摘　　要：Time-resolved electron spin resonance has been used to study quenching reactions between the antioxidant Vitamin C （VC） and the triplet excited states of 9,10-phenanthrenequinone （PAQ） in ethylene glycol-water （EG-H2O） homogeneous and inhomogeneous reversed micelle solutions. Reversed micelle solutions were used to be the models of physiological environment of biological cell and tissue. In PAQ/EG-H2O homogeneous solution, the excited triplet of PAQ （3PAQ＊） abstracts hydrogen atom from solvent EG. In PAQ/VC/EG-H2O solution, 3pAQ＊ abstracts hydrogen atom not only from solvent EG but also from VC. The quenching rate constant of 3pAQ＊ by VC is close to the diffusion-controlled value of 1.41 × 108 L/（mol.s）. In hexadecyltrimethylammonium bromide （CTAB）/EG-H2O and aerosol OT （AOT）/EG- H2O reversed micelle solutions, 3pAQ＊ and VC react around the water-oil interface of the reversed micelle. Exit of 3pAQ＊ from the lipid phase slows down the quenching reaction. For Triton X-100 （TX-100）/EG-H2O reversed micelle solution, PAQ and VC coexist inside the hydrophilic polyethylene glycol core, and the quenching rate constant of 3pAQ＊ by VC is larger than those in AOT/EG-H2O and CTAB/EG-H2O reversed micelle solutions, even a little larger than that in EG-H2O homogeneous solution. The strong emissive chemically induced dynamic electron polarization of As＇- resulted from the effective TM spin polarization transfer in hydrogen abstraction of 3pAQ＊ from VC.

关 键 词：9 10-phenanthrenequinone Vitamin C Time-resolved electron spin resonance Reversed micelle 

分 类 号：O[理学]