物理化学学报 >> 1993, Vol. 9 >> Issue (05): 635-641.doi: 10.3866/PKU.WHXB19930513

研究论文 上一篇    下一篇

铜(II)与四(间甲基)苯基卟啉镉(II)取代反应动力学

朱志昂; 黄小群; 陈荣悌   

  1. 南开大学化学系,天津 300071
  • 收稿日期:1992-04-10 修回日期:1992-09-02 发布日期:1993-10-15
  • 通讯作者: 朱志昂

Kinetic Study of the Electrophilic Substitution Reaction of Copper ion with Meso-tetrakis (Meta-methylphenyl) Porphyrin Cadmium (II)

Zhu Zhi-Ang; Huang Xiao-Qun; Chen Rong-Ti   

  1. Department of Chemistry, Nankai University, Tianjin 300071
  • Received:1992-04-10 Revised:1992-09-02 Published:1993-10-15
  • Contact: Zhu Zhi-Ang

摘要: 用分光光度法研究了二甲亚砜溶液中, 氯化铜与meso-四(间甲基)苯基卟啉镉(Ⅱ)(Cd(Ⅱ)P)亲电取代反应的动力学. 讨论了影响反应的因素,
CuCl_2+Cd(Ⅱ)P→Cu(Ⅱ)P+CdCl_2
提出了反应机理并进行了验证. 用AST286微机对实验数据进行非线性最小二乘法拟合, 得到拟合曲线及似平衡步的平衡常数K及其它基元步骤的速率常数k_1, k_(-1), k_2. 研究了温度对反应的影响, 求得似平衡步的△_rH_m~-θ-, △_rS_m~-θ-及其它基元步骤的活化参数△~≠H_m, △~≠S_m.

关键词: 四(间甲基)苯基卟啉镉(II), 取代反应动力学, 反应机理

Abstract: Kinetics of the electrophilic substitution reaction (1) of
CuCl_2+Cd(Ⅱ)P→Cu(Ⅱ)P+CdCl_2 (1)
cupric chloride with meso-tetrakis(meta-methylphenyl) porphyrin cadmium(Ⅱ) was studied by means of Shimadzu UV-240 spectrophotometer. The proposed mechanism is as follows:
Cd(Ⅱ)P+Cl~-<=>[Cd(Ⅱ)PCl]~- (2)
Cu(Ⅱ)+[Cd(Ⅱ)PCl]~-<=>[Cu(Ⅱ)PCl]~-+Cd(Ⅱ) (3)
[Cu(Ⅱ)PCl]~-→Cu(Ⅱ)P+Cl~- (4)
The experimental data were treated with AST-286 microcomputer. The equilibrim constant(K) of preequilibrium step(1) and the rate constants(k_1, k_(-1), k_2) of step (2) and step (3) were obtained. The standard molar enthalpy change △_rH_m~-θ-, and standard entropy change △_rS_m~-θ-, of step (1) and the activation parameters Δ~≠H_(m,1), Δ~≠H_(m,-1), Δ~≠H_(m,2) and Δ~≠S_(m,1), Δ~≠S_(m,-1), Δ~≠S_(m,2) were calculated.

Key words: Tetrakis (Meta-methylphenyl) Porphyrin Cadmium (II), Kinetics of Substitution reaction, Mechanism of reaction