影像科学与光化学 ›› 1989, Vol. 7 ›› Issue (4): 50-57.DOI: 10.7517/j.issn.1674-0475.1989.04.50

• 研究论文 • 上一篇    下一篇

钴(Ⅲ)络合物氧化对苯二胺类化合物的动力学与机理的研究

毛英, 周本茂, 任新民   

  1. 中国科学院感光化学研究所, 北京 100012
  • 收稿日期:1988-06-03 修回日期:1989-07-03 出版日期:1989-11-20 发布日期:1989-11-20
  • 通讯作者: 任新民

THE KINETICS AND MECHANISM OF OXIDATION OF P-PHENYLENE-DIAMINES WITH Co(Ⅲ)-COMPLEXES

MAO YING, ZHOU BEN-MAO, REN XIN-MIN   

  1. Institute of Photographic Chemistry, Academia Sinica, Beijing 100012, P.R. China
  • Received:1988-06-03 Revised:1989-07-03 Online:1989-11-20 Published:1989-11-20

摘要: 本文通过监测氧化中间体半醌(S+)的吸光度变化跟踪反应进程。用初始速率法处理得到了HAc-NaAc介质中Fe(CN)63-(Ox′)催化[CO(NH3)5Cl]2+(Ox)氧化CD-4遵循下列动力学方程:
d[S+]/dt=kobs.[Ox′]0.90[Ox]0.85
认为Fe(CN)63-的再生过程是整个反应的决速步骤。估算了决速步的速率常数k(298K)、活化焓△H0≠和活化熵分别为1.92dm3·mol-1s-1、23.1kcal/mol和20.5cal/mol.K。以TEPPD代替CD-4、以Fe(CN)64-代替Fe(CN)63-的实验结果支特T所提出的再生机理的合理性。

关键词: 钴(Ⅲ)络合物, 对苯二胺类化合物, 氧化, 动力学, 超加和氧化机理

Abstract: The oxidation of CD-4 with [CO(NH3)5Cl]2+(Ox) catalyzed by Fe(CN)63-(Ox′) was investigated in HAc-NaAc buffer solution by means of initial rate method. The empirical rate equation is:The regeneration of Fe(CN)63- is regarded as the rate-determing step. The rate cons" tant(298K) and activation parameters have been evaluated. The results obtained with TEPPD instead of CD-4 or Fe(CN)64- instead of Fe(CN)63- suport the suggested regeneration mechanism.The empirical rate equation of direct oxidation of CD-4 or TEPPD with [Coen2Cl2]+ has been formulated. The activation energy was measured. The rate-determing step may be the oxidation of PPD to S+.The experimental results of oxidation of PPD with [Co(NH3)6]3+ [Co111en3]3+; [CO(NH3)5Cl]2+(Ox) and [Coen·Cl2]+ showed that the oxidizing ability of the Co(III)-complexes decreases with their substitution inertness.

Key words: Cobalt (Ⅲ)-complexes, oxidation, kinetics, p-phenylene-diamines, superadditive oxidation mechanism