Yin Yao-Peng, Dong Chen-Zhong, Ding Xiao-Bin
J Phys Chem A. 2015 Apr 2;119(13):3253-60. doi: 10.1021/jp511265j. Epub 2015 Mar 19.
The equilibrium structures, vibrational frequencies, and bond characteristics of NpO2(m+) ions and NpO2(H2O)n(m+) (m = 1-2, n = 1-6) complexes have been studied by carrying out ab initio calculations in the gas phase and aqueous solution. The geometries have been obtained at the B3LYP level with the use of the polarized continuum model (PCM). The computed structural parameters that are in reasonably good agreement with the available data show that the solvation effect leads to a red shift of the IR spectra and the weakness of interaction strengths in neptunyl ions. By comparing the structural properties and the density of states (DOS) of these aqua complexes in the gas phase and aqueous solution, it is found that the solvation effect can be simulated approximately with the calculations of these aqua complexes in the gas phase. In addition, the DOS of these aqua complexes together with the binding energies between the neptunyl ion and water molecule reveal that the penta-aqua complex is preferred for neptunyl ions in aqueous solution.
通过在气相和水溶液中进行从头算计算，研究了NpO2(m+)离子和NpO2(H2O)n(m+)（m = 1 - 2，n = 1 - 6）配合物的平衡结构、振动频率和键特征。使用极化连续介质模型（PCM）在B3LYP水平上获得了几何结构。计算得到的结构参数与现有数据相当吻合，表明溶剂化效应导致红外光谱发生红移以及镎酰离子中相互作用强度减弱。通过比较这些水合配合物在气相和水溶液中的结构性质和态密度（DOS），发现溶剂化效应可以通过在气相中计算这些水合配合物来近似模拟。此外，这些水合配合物的态密度以及镎酰离子与水分子之间的结合能表明，在水溶液中镎酰离子优先形成五水合配合物。
