Virca Carolyn N, McCormick Theresa M
Portland State University, College of Liberal Arts & Sciences, Department of Chemistry, Post Office Box 751 CHEM, Portland, Oregon 97207, USA.
Dalton Trans. 2015 Aug 28;44(32):14333-40. doi: 10.1039/c5dt02044a.
Nickel pyridine 2-thiolate (Ni(PyS)3(-)) has shown good stability and activity as a H2 generation catalyst for use in solar energy storage. The experimentally proposed catalytic pathway is explored using DFT calculations. Free energy changes along the reaction coordinate, spin states, localization of charge and geometry of the intermediates were explored. Calculations were performed using Gaussian 09 with a B3P86/6-31+G(d) basis set and a CPCM water solvation model. Of particular interest were our findings that the first reduction occurs at the nickel rather than through non-innocent ligands and that water coordination is not favourable although protonation of the pyridyl nitrogen causes dechelation. Sequential and concerted proton coupled electron transfer were considered in the formation of the hydride.
吡啶-2-硫醇镍（Ni(PyS)₃⁻）作为用于太阳能存储的产氢催化剂，已显示出良好的稳定性和活性。使用密度泛函理论（DFT）计算探索了实验提出的催化途径。研究了沿反应坐标的自由能变化、自旋态、电荷局域化以及中间体的几何结构。计算使用高斯09程序，采用B3P86/6 - 31 + G(d)基组和CPCM水溶剂化模型。我们特别感兴趣的发现是，首次还原发生在镍上而非通过非无辜配体，并且尽管吡啶氮的质子化导致螯合作用解除，但水配位并不有利。在氢化物形成过程中考虑了顺序和协同的质子耦合电子转移。
