| 维生素C对菲醌三重激发态的淬灭机理及动力学研究 |
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| 引用本文： | 许新胜,史蕾,刘毅,季学韩,崔执凤.维生素C对菲醌三重激发态的淬灭机理及动力学研究[J].化学物理学报,2011,24(2):150-154. |
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| 作者姓名： | 许新胜 史蕾 刘毅 季学韩 崔执凤 |
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| 作者单位： | 安徽师范大学原子与分子物理研究所，芜湖241000;安徽师范大学原子与分子物理研究所，芜湖241000;安徽师范大学原子与分子物理研究所，芜湖241000;安徽师范大学原子与分子物理研究所，芜湖241000;安徽师范大学原子与分子物理研究所，芜湖241000 |
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| 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上夺氢，还从VC上夺氢，VC对3PAQ*的淬灭速率常数为1.409×108 L/(mol·s)， 反应受扩散控制． 在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增溶于亲水的聚氧乙烯链中，VC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．很强的VC负离子自由基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
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| 关 键 词： | 菲醌，维生素C，时间分辨电子自旋共振，反胶束 |
| 收稿时间： | 2010/12/4 0:00:00 |
TR-ESR Investigation on Reaction of Vitamin C with Excited Triplet of 9,10-phenanthrenequinone in Reversed Micelle Solutions |
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| Xin-sheng Xu,Lei Shi,Yi Liu,Xue-han Ji and Zhi-feng Cui.TR-ESR Investigation on Reaction of Vitamin C with Excited Triplet of 9,10-phenanthrenequinone in Reversed Micelle Solutions[J].Chinese Journal of Chemical Physics,2011,24(2):150-154. |
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| Authors: | Xin-sheng Xu Lei Shi Yi Liu Xue-han Ji and Zhi-feng Cui |
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| Institution: | Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu 241000, China;Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu 241000, China;Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu 241000, China;Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu 241000, China;Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu 241000, China |
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| Abstract: | 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 in-duced dynamic electron polarization of As- resulted from the effective TM spin polarization transfer in hydrogen abstraction of 3PAQ* from VC. |
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| Keywords: | 9 10-phenanthrenequinone Vitamin C Time-resolved electron spin resonance Reversed micelle |
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