化学学报 ›› 2011, Vol. 69 ›› Issue (11): 1375-1380. 上一篇    

研究论文

电子自旋共振作为探针研究卤代溶剂的专属性效应

庞雪,申前进,赵晓冉,晋卫军*   

  1. (北京师范大学化学学院 北京 100875)
  • 收稿日期:2010-07-28 修回日期:2010-12-15 出版日期:2011-06-14 发布日期:2011-01-27
  • 通讯作者: 晋卫军 E-mail:wjjin@bnu.edu.cn
  • 基金资助:

    国家自然科学基金项目

Investigation on Specific Effect of Halogenated Solvents by ESR Probe

PANG Xue, SHEN Qian-Jin, ZHAO Xiao-Ran, JIN Wei-Jun   

  1. (College of Chemistry, Beijing Normal University, Beijing 100875)
  • Received:2010-07-28 Revised:2010-12-15 Online:2011-06-14 Published:2011-01-27
  • Contact: Wei Jun Jin E-mail:wjjin@bnu.edu.cn

4-羟基-2,2,6,6-四甲基哌啶-1-氧自由基(4-OH-TEMPO)电子自旋共振的超精细耦合常数AN与溶剂极性的微观反应常数ET(30)和溶剂受体数AN呈现线性正相关. 并且在介电常数或偶极矩接近时, 含卤溶剂中超精细耦合常数AN普遍偏高. 除了一般的溶剂效应外, 在含卤溶剂中超精细耦合常数AN偏大的原因与专属性的卤键作用有关. 理论计算结果辅助印证了这一结论.

关键词: 卤键, 电子自旋共振, 专属性溶剂效应, 含卤溶剂, 溶剂受体数

The hyperfine splitting constants, AN, of electron spin probe, 4-hydroxy-2,2,6,6-tetramethyl-1- piperidin-1-yloxy, free radical (4-OH-TEMPO) show positive linear correlation with model reaction parameters of solvent polarity, ET(30) and solvent acceptor number (AN). Moreover, generally, AN values are higher in halogenated than non halogenated solvents as dielectron constant or dipole moment is near. Besides the general solvent effect on AN values, larger AN values can be attributed to the specific halogen-bonding between N—O free radical and halogenated solvent molecule. The calculation shows the occurrence of C—Cl…O between chloroform or dichloromethane and free radical molecules.

Key words: halogen-bonding, electron spin resonance, specific solvent effect, halogenated solvent, solvent acceptor number