物理化学学报 >> 2005, Vol. 21 >> Issue (11): 1235-1239.doi: 10.3866/PKU.WHXB20051108

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计时电量法求NiCl2(bpy)3在DMF中的扩散系数和速率常数

赵鹏; 方慧珏; 薛腾; 亓西敏; 陆嘉星   

  1. 华东师范大学化学系, 上海市绿色化学与化工过程绿色化重点实验室, 上海 200062
  • 收稿日期:2005-03-24 修回日期:2005-05-20 发布日期:2005-11-15
  • 通讯作者: 陆嘉星 E-mail:jxlu@chem.ecnu.edu.cn

Diffusion Coefficients and Rate Constants of NiCl2(bpy)3 in DMF Determined by Chronocoulometry

ZHAO Peng; FANG Hui-jue; XUE Teng; QI Xi-min; LU Jia-xing   

  1. Shanghai Key Laboratory of Green Chemistry and Chemical Process, Department of Chemistry, East China Normal University, Shanghai 200062
  • Received:2005-03-24 Revised:2005-05-20 Published:2005-11-15
  • Contact: LU; Jia-xing E-mail:jxlu@chem.ecnu.edu.cn

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摘要： 讨论了NiCl2(bpy)3(bpy：2,2-联吡啶)在DMF中的电化学行为. 控制电位使电极过程处于扩散控制下, 采用计时电量法求得了29 ℃时NiCl2(bpy)3在DMF中的扩散系数为5.99×10－6 cm2•s-1, 不同温度下的扩散系数随温度升高而增大. 选择合适的电极电位, 使电极过程处于扩散和电化学混合控制下, 采用计时电量法求得了不同电极电位下的反应速率常数kf, 以及不同温度下的标准速率常数k0, 求得了表观活化能为14.4 kJ•mol-1.

关键词: 镍配合物, 计时电量, 速率常数, 扩散系数, 活化能

Abstract: The electrochemical characteristic of NiCl2(bpy)3 at glassy carbon electrode in DMF has been investigated by using cyclic voltammetry. Chronocoulometry was employed to determine the diffusion coefficients and the rate constants (kf and k0). The CV results imply that the redox reaction of NiCl2(bpy)3 at glassy carbon electrode is quasi-reversible. The diffusion coefficient increased with the increase of temperature between 302.15 K and 334.15 K. The forward rate constants (kf) at different potentials and standard rate constants (k0) at different temperatures were also obtained by analysis of charge-time data. According to the slope of lnk0 against T-1, the activation energy (Ea) of the electron transfer was 14.4 kJ•mol-1.

Key words: Nickel complex, Chronocoulometry, Rate constant, Diffusion coefficient, Activation energy