Moens Jan, Roos Goedele, Jaque Pablo, De Proft Frank, Geerlings Paul
Eenheid Algemene Chemie, Faculteit Wetenschappen, Vrije Universiteit Brussel (VUB), Pleinlaan 2, Brussels, Belgium.
Chemistry. 2007;13(33):9331-43. doi: 10.1002/chem.200700547.
Previous contributions concerning the computational approach to redox chemistry have made use of thermodynamic cycles and Car-Parrinello molecular dynamics simulations to obtain accurate redox potential values, whereas this article adopts a conceptual density functional theory (DFT) approach. Conceptual DFT descriptors have found widespread use in the study of thermodynamic and kinetic aspects of a variety of organic and inorganic reactions. However, redox reactions have not received much attention until now. In this contribution, we prove the usefulness of global and local electrophilicity descriptors for the prediction of the redox characteristics of first row transition metal ions (from Sc(3+) | Sc(2+) to Cu(3+) | Cu(2+)) and introduce a scaled definition of the electrophilicity based on the number of electrons an electrophile ideally accepts. This scaled electrophilicity concept acts as a good quantitative estimate of the redox potential. We also identify the first solvation sphere together with the metal ion as the primary active region during the electron uptake process, whereas the second solvation sphere functions as a non-reactive continuum region.
先前关于氧化还原化学计算方法的研究利用热力学循环和Car-Parrinello分子动力学模拟来获得准确的氧化还原电位值，而本文采用了一种概念性密度泛函理论（DFT）方法。概念性DFT描述符已在各种有机和无机反应的热力学和动力学研究中得到广泛应用。然而，氧化还原反应至今尚未受到太多关注。在本研究中，我们证明了全局和局部亲电性描述符对于预测第一行过渡金属离子（从Sc(3+) | Sc(2+)到Cu(3+) | Cu(2+)）的氧化还原特性的有用性，并基于亲电体理想接受的电子数引入了亲电性的标度定义。这种标度亲电性概念可作为氧化还原电位的良好定量估计。我们还确定了在电子摄取过程中，与金属离子一起的第一溶剂化层是主要的活性区域，而第二溶剂化层则作为非反应性连续区域。
