【摘要】 应用循环伏安法研究了哌啶氮氧自由基(1—3)在酸性甲醇中的电化学可逆氧化和还原特性。实验表明这些氮氧自由基可视为电子受体及给体的良好模型化合物,且1—3在酸性的非水溶液中的还原反应进行得很快,而减少酸性将有利于其氧化反应。更多还原

【Abstract】 In this work the electrochemical redox reactions of three piperidine nitroxides (1-3) in methanol were investigated for the purpose of elucidating the mechanism of their electron-transfer (ET) processes. Cyclic voltammctric studies on 1-3 in acidic methanol solution have clearly demonstrated that both electrochemical reduction and oxidation show reversible ET characteristics. Both E1/3red and E1/2ox with approximate values of -0.28V and 0.70V respectively, indicate that these nitroxides can be regarded as good models of electron acceptors and donors. It was further found that reduction currents (RC) were considerably larger than oxidation currents (OC) under the same conditions. Moreover, RC increased rapidly as the acidity of the medium increased, whereas OC decreased slightly with increasing acidity of the medium. These results verify that reduction of 1-3 in acidic nonaqueous solution is expected to procced rapidly and that in weak acidic medium the oxidation of 1-3 should be favored.更多还原