物理化学学报 >> 2003, Vol. 19 >> Issue (03): 268 -271 .doi: 10.3866/PKU.WHXB20030318

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激光光解苯醌自由基质子交换的TRESR研究

陆同兴;许新胜;崔执凤   

  1. 安徽师范大学光谱与材料研究室,芜湖 241000
  • 收稿日期:2002-06-07 修回日期:2002-09-25 发布日期:2003-03-15
  • 通讯作者: 陆同兴 E-mail:txlu@mail.ahnu.edu.cn

Investigation on the TRESR Spectra of the Laser Photolyzed Benzoquinone Radical under Proton Exchange

Lu Tong-Xing;Xu Xin-Sheng;Cui Zhi-Feng   

  1. Laboratory of Spectroscopy and Materials, Anhui Normal University, Wuhu 241000
  • Received:2002-06-07 Revised:2002-09-25 Published:2003-03-15
  • Contact: Lu Tong-Xing E-mail:txlu@mail.ahnu.edu.cn

摘要: 用时间分辨电子自旋共振(TRESR)波谱仪,研究了对苯醌/乙二醇/水体系中激光光解苯醌自由基的TRESR谱的线形与溶液pH值的关系.实验表明TRESR谱线均为发射极极化,极化过程以三重态机理(TM)为主.在中性溶液中谱线属中性苯半醌自由基BQH•,而在pH~2.02酸性溶液中谱线属阳离子基BQH+.实验发现 BQH+的TRESR谱强度的衰减具有超精细分量相关性,用质子交换理论对此进行了解释.

关键词: 光解对苯醌自由基, 化学诱导动态电子极化, 时间分辨电子自旋共振, 质子交换, 苯醌阳离子基

Abstract: The proton exchange of the benzoquinone radicals obtained from the laser photolysis of p-benzoquinone in ethylene glycol/water system was investigated by using time-resolved ESR(TRESR)spectrometer. The dependence of the TRESR spectra upon the pH value of the mixed solution was studied. In neutral solution, six superfine emission lines were observed and were attributed to radical BQH•, while the pH value of the solution changed to ~2.0, five emission superfine lines were observed and were assigned to cation BQH+. For BQH+, the decay rates differ in the superfine lines, lines involving greater fraction of the nuclear spin states decayed with slower rates than those involving smaller ones owing to the variation of the resonance position in the proton exchange.

Key words: Photolyzed p-benzoquinone radical, Chemically induced dynamic electron polarization (CIDEP), Time resolved electron spin resonsnce(TRESR),  Proton exchange, Benzoquinone cation