Application of Non-Steady-State Kinetics to Resolve the Kinetics of Proton-Transfer Reactions between Methylarene Radical Cations and Pyridine Bases
作者:Vernon D. Parker、Yixing Zhao、Yun Lu、Gang Zheng
DOI:10.1021/ja982682k
日期:1998.12.1
base reactions in dichloromethane (0.2 M tetrabutylammonium hexafluorophosphate) were observed to increase toward a constant value with increasing extent of reaction. The reactions were studied by derivative cyclic voltammetry (DCV), and rate constants were assigned by comparing the experimental with the theoretical DCV data. The kinetic results rule out a simple second-order proton-transfer reaction
观察到在二氯甲烷(0.2 M 四丁基六氟磷酸铵)中的四种不同甲基芳烃自由基阳离子-吡啶碱反应的表观氘动力学同位素效应(KIEapp)随着反应程度的增加而向恒定值增加。通过导数循环伏安法 (DCV) 研究反应,并通过将实验与理论 DCV 数据进行比较来指定速率常数。动力学结果排除了简单的二级质子转移反应,并暗示了一种机制,其中首先形成复合物,然后进行质子转移,然后分离产物。在达到稳态之前观察到 KIEapp 是反应依赖程度。