Periyasamy Ganga, Sour Angelique, Collin Jean-Paul, Sauvage Jean-Pierre, Remacle Françoise
Chemistry Department, B6c, University of Liege, B4000 Liege, Belgium.
J Phys Chem B. 2009 May 7;113(18):6219-29. doi: 10.1021/jp901214b.
A mechanism for the electrochemically driven reorganization of a model copper [2]pseudorotaxane is proposed on the basis of density functional theory computations and validated by comparing to experimental results. We investigate in detail the ligand reorganization around the Cu ion from a 4 to 5 coordination number that follows the conversion of the oxidation state from +1 to +2. It is found that for both the oxidation and the reduction processes the rearrangement proceeds in a concerted fashion via a single transition state. Energy paths involving stable decoordinated-coordinated intermediates are computed to be higher in energy. The cyclic voltammogram simulated using the computed transition theory state rate constants in solvent medium is in good agreement with the experimental voltammogram. Further, we report on the computed concentration change of stable (Cu(+)(4), Cu(2+)(5)) and metastable species (Cu(2+)(4), Cu(+)(5)) during single cyclic voltammetry (CV) cycle as a function of the applied voltage or time (the subscripts 4 and 5 refer to the coordination number of the copper center).
基于密度泛函理论计算，提出了一种电化学驱动的模型铜[2]准轮烷重组机制，并通过与实验结果比较进行了验证。我们详细研究了随着氧化态从 +1 转变为 +2，铜离子周围配体从 4 配位到 5 配位的重组过程。结果发现，对于氧化和还原过程，重排均通过单一过渡态以协同方式进行。计算得出涉及稳定的去配位 - 配位中间体的能量路径在能量上更高。使用计算出的过渡理论状态速率常数在溶剂介质中模拟的循环伏安图与实验伏安图吻合良好。此外，我们报告了在单循环伏安法（CV）循环期间，稳定物种（Cu(+)(4)、Cu(2+)(5)）和亚稳物种（Cu(2+)(4)、Cu(+)(5)）的计算浓度变化与施加电压或时间的函数关系（下标 4 和 5 指铜中心的配位数）。
