【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θ_β值大小与处于不同位置的给定取代基R的关系为:θ_β（O—R）<θ_β（m—R）<θ_β（P—R）更多还原

【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 angleθβ can be obtained and the effects of the same substituent in different ring positions of θβ are in the order ofθβ (o-R ) <θβ( m-R ) <θβ (p-R )更多还原