中文摘要：

用时间分辨电子自旋共振技术研究了乙二醇（EG）均相溶液和反胶束溶液中抗氧化剂维生素C（VC）对菲醌（PAQ）分子激发三重态3PAQ＊的淬灭反应．利用反胶束模拟生物细胞和组织的生理环境，光解PAQ／EG-H2O均相溶液，3PAQ＊与溶剂分子EG之间发生氢转移反应．当体系中加入VC后，3PAQ＊不仅从EG上夺氧，还从VC上夺氧，VC对3PAQ＊的淬灭速率常数为1．409×108L／（mol.s），反应受扩散控制．存CTAB／EG—H2O和AOT／EG—H2O反胶束溶液中，3PAQ＊和VC之间的夺氢反应发生在反胶束的水／油界面附近，3PAQ＊扩散到油／水界面的过程降低了反应的速率．对于TX-100／EG—H2O反胶束溶液，由于PAQ增深于亲水的聚氧乙烯链中，VCX对3PAQ＊的淬灭速率常数比CTAB／EG—H2O和AOT／EG-H2O反胶束中的都大，甚至比EG—H2O均相溶液中的也略大．微强的VC负离了自由基As-的CIDEP信号来源于3PAQ＊与VC之间发生抽氢反应过程中的三重态机理自旋极化转移．

英文摘要：

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.