J4 ›› 2011, Vol. 28 ›› Issue (3): 271-277.

• 光谱 • 上一篇    下一篇

激光诱导萘醌激发三重态猝灭反应的TR-ESR研究

许新胜,汪建,晏菁,朱光来,崔执凤   

  1. 安徽师范大学原子与分子物理研究所,安徽 芜湖 241000
  • 收稿日期:2010-12-16 修回日期:2010-12-21 出版日期:2011-05-28 发布日期:2011-05-20
  • 通讯作者: 许新胜(1975-),安徽宣城人,理学博士,副教授,主要从事原子与分子光谱理论及实验研究。 E-mail:xxsheng@mail.ahnu.edu.cn
  • 基金资助:

    国家自然科学基金(20903004),安徽高校省级自然科学研究重点项目(KJ2010A145)

A TR-ESR investigation on the quenching reaction of laser induced excited triplet state of 1,4-naphthoquinone

XU Xin-sheng, WANG Jian, YAN Jing, ZHU Guang-Lai, CUI Zhi-Feng   

  1. Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu 241000, China
  • Received:2010-12-16 Revised:2010-12-21 Published:2011-05-28 Online:2011-05-20
  • Supported by:

    国家自然科学基金(20903004),安徽高校省级自然科学研究重点项目(KJ2010A145)

摘要:

利用时间分辨电子自旋共振(TR-ESR)方法,研究了稳定自由基TEMPO和生物抗氧化剂维生素C(VC)对萘醌(NQ)激发三重态 的猝灭机理和猝灭动力学。光解NQ/EG体系, 从EG上抽氢生成萘醌中性自由基 和乙二醇碳自由基。当体系中加入稳定自由基TEMPO时,TEMPO对3NQ* 有明显的猝灭作用,猝灭速率常数为1.14*106Lmol-1s-1。对于NQ/VC/EG-H2O溶液,3NQ*不仅可以从EG上夺氢,还从VC上夺氢,VC对3NQ*也有明显的猝灭作用,猝灭速率常数为1.11*107Lmol-1s-1。TEMPO和VC对3NQ*的猝灭反应都受扩散控制。

关键词: 光谱, 萘醌, TEMPO, 维生素C, 时间分辨电子自旋共振

Abstract:

The reaction mechanism and dynamics of the laser induced excited triplet of 1,4-naphthoquinone ( ) quenched by TEMPO and biological antioxidant vitamin C (VC) were investigated by means of spectroscopy(TR-ESR) method. During the photolysis of NQ/EG (ethylene glycol) solution, abstracts hydrogen atom from solvent molecule EG and the neutral radical and EG ketyl radical were generated. When TEMPO was added into NQ/EG solution, TEMPO is an effective quencher of and the quenching rate constant is . For NQ/VC/EG-H2O solution, abstracts hydrogen atom not only from solvent EG but also from VC. VC is also an effective quencher of and the quenching rate constant is . The quenching reactions of by TEMPO and VC are both controlled by diffusion.

Key words: spectroscopy, 1,4-naphthoquinone, TEMPO, vitamin C, time resolution electron spin resonance

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