关键词: 循环伏安法, 对苯二胺化合物, 脱氨反应, 彩色显影

Abstract: The kinetics and mechanism of the deamination of N-substimted quinonediimines and N-substituted quinone monoimines were examined as a function of increasing pH. In this work, the rate constants of the deamination were determined with a semiempirical procedure of stationary electrode polarography.Deamination is initiated by nucleophilic attack on the most positively charged carbon atom of the benzene ring. Therefore, electron donating substituent has an effect on the rates of deamination and half-wave potential. Under the same condition, the half-wave potential of 2-methyl substituted compound is ca. 120 mV lower than the unsubstituted one. The absorption maximum of the dye formed by a methyl-substituted quinonediimine with the coupler would shift about 20-30 nm to the longer wavelength when compared with the unsubstituted compound.

Key words: Cyclovoltammetry, Phenylenediamine, Deamination, Color development