波谱学杂志 ›› 1987, Vol. 4 ›› Issue (1): 29-33.

• 研究论文 • 上一篇    下一篇

电极过程自由基中间体的ESR研究——取代苯基重氮盐的电解还原

刘扬1, 徐广智1, 赵瑶兴2, 孙祥玉2   

  1. 1. 中国科学院化学研究所 北京;
    2. 中国科技大学研究生院 北京
  • 收稿日期:1986-07-16 出版日期:1987-03-05 发布日期:2018-01-22
  • 基金资助:
    国家自然科学基金委员会资助

ESR STUDY OF THE FREE RADICAL INTERMEDIATES FORMED DURING THE ELECTROLYTIC PROCESS-ELECTROLYTIC REDUCTION OF SUBSTITUTED PHENYLDIAZONIUM SALTS

Liu Yang1, Xu Guangzhi1, Zhao Yaoxing2, Suen Xiangyu2   

  1. 1. Institute of Chemistry, Academia Simica, Beijing;
    2. Graduate School, Academia Sinica, Beijing
  • Received:1986-07-16 Online:1987-03-05 Published:2018-01-22

摘要: 本文用自由基捕捉剂苯亚甲基叔丁基氮氧化物(PBN)与ESR相结合的方法研究了十种取代苯基重氮盐RC6H4N2+BF4-(R=F,Cl,Br,NO2,OCH3及CH3)在乙腈中电解还原产生的活泼自由基。
结果表明:
1.RC6H4N2+BF4-电解还原时产生RC6H4自由基,并能被捕捉剂PBN所捕捉,以形成稳定的自由基加合物[RC6H4-PBN]·
2.由[RC6H4-PBN]·ESR谱的超精细裂分常数算出的二面角θβ值大小与处于不同位置的给定取代基R的关系为:
θβ(O-R) < θβ(m-R) < θβ(P-R)

关键词: 重氮盐, 电解还原, 自旋捕捉, 电子自旋共振

Abstract: Free radicals produced by the electroreduction of substituted phenyldiazo-nium RC6H4N2+BF4-(R=F, Cl,Br,NO2,OCH3, or CH3) in acetonitrile were studied with the combination of ESR spectroscopy with spin trapping technique.The results show that:
1. Radical RC6H4·is produced during the electroreduction of RC6H4N2+BF4-, and it can be trapped by PEN to form stable spin adduct (RC6H4-PBN)·.
2. From the hyper-fine splitting constant of the spin adduct, the dihedral angle θβ can be obtained and the effects of the same substituent in different ring positions of θβ are in the order of
θβ (o-R) < θβ(m-R) < θβ (p-R)

Key words: arenediazonium, electroreduction, Spin trapping, ESR