本文研究了在不同pH值的水溶液中电化学还原产生的硝基苯阴离子基的ESR谱。随pH值下降,硝基苯阴离子基的ESR谱由54条线变为36条线。这种变化主要是硝基苯分子与其阴离子基之间电子交换速度增大,ESR谱线增宽,谱分辨率下降造成的。谱的理论模拟也证明了这一点。交换速度常数在强碱介质中约为3.3×10~6s~(-1)·mol~(-1)·dm~3。 In this paper, the ESR spectra of nitrobenzene anions generated by electrochemical reduction in aqueous solutions of different pH were studied. With the decrease of pH, the ESR spectrum of nitrobenzene anion changed from 54 lines to 36 lines. This change is mainly due to the electron exchange rate between nitrobenzene and its anion group increased, ESR spectrum broadened, the spectral resolution decreased. Theoretical simulation of the spectrum also proves this. The exchange rate constant is about 3.3 × 10 ~ 6s ~ (-1) · mol ~ (-1) · dm ~ 3 in strong alkaline medium.