碱性介质中分光光度法研究二过碘酸合铜(III)氧化1,2-丙二胺反应动力学及机理  

Kinetics and Mechanism of Oxidation of 1,2-Propanediamine by Diperiodatocuprate(III) with spectrophotometry in Alkaline Medium

作　　者：王立平[1] 单金缓[2] 孙汉文[2] 

机构地区：[1]保定学院生化系,河北保定071000 [2]河北大学化学与环境科学学院河北省分析科学与技术重点实验室,河北保定07100

出　　处：《安徽师范大学学报（自然科学版）》2013年第3期254-258,共5页Journal of Anhui Normal University(Natural Science)

基　　金：河北省自然科学基金(295066)

摘　　要：在碱性介质中,用分光光度法研究了二过碘酸合铜(III)配离子(DPC)氧化1,2-丙二胺(PDA)的反应动力学及机理.结果表明,反应对DPC为一级,对PDA为1<nap<2(nap代表表观反应级数);在保持准一级条件([PDA]0[Cu(III)]0)下,表观速率常数kobs随[OH-]增大而增大,随着[IO-4]增加而减小,且有负盐效应.提出了包括配离子和1,2-丙二胺形成络合物的前期快速平衡的反应机理,由假设的反应机理推出的速率方程能很好的解释全部实验现象,并进一步求得速控步的速率常数和活化参数.The kinetics of oxidation of 1,2-propanediamine （PDA） by diperiodatocuprate（Ⅲ） complex （DPC） was studied spectrophotometrically in alkaline medium. The reaction rate showed first order dependence in DPC and 1 〈 nap〈 2 in PDA. It was found that under the conditions of the pseudo-first order （[PDA]0〉〉[Cu （Ⅲ）10）, the rate constant kobs iricreased with increase in [OH-], and then it decreased with increase in [ IO4-]. There is a negative salt effect. A plausible mechanism involving a pre-equilibrium of an adduct formation between the complex and PDA was proposed. The rate equations derived from mechanisms can explain all experimental results. The activation parameters along with the rate constants of the rate-determining step were calculated.

关 键 词：二过碘酸合铜(Ⅲ) 1 2-丙二胺 氧化还原反应 动力学及机理 

分 类 号：O643.11[理学—物理化学]