School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
J Phys Chem A. 2013 Jun 27;117(25):5385-91. doi: 10.1021/jp405052g. Epub 2013 Jun 13.
The structure and bonding in ionized water clusters, (H2O)(n)(+) (n = 3–9), has been studied using the basin hopping search algorithm in combination with quantum chemical calculations. Initially candidate low energy isomers were generated using basin hopping in conjunction with density functional theory. Subsequently, the structures and energies were refined using second order Møller–Plesset perturbation theory and coupled cluster theory, respectively. The lowest energy isomers are found to involve proton transfer to give H(3)O(+) and a OH radical, which are more stable than isomers containing the hemibonded hydrazine-like fragment (H(2)O–OH(2)), with the calculated infrared spectra consistent with experimental data. For (H(2)O)(9)(+) the observation of a new structural motif comprising proton transfer to form H(3)O(+) and OH, but with the OH radical involved in hemibonding to another water molecule is discussed.
已使用结合量子化学计算的 basin hopping 搜索算法研究了离子化水分子团簇 (H2O)(n)(+) (n = 3-9) 的结构和键合。最初，使用 basin hopping 结合密度泛函理论生成候选低能量异构体。随后，分别使用二阶 Møller-Plesset 微扰理论和耦合簇理论对结构和能量进行了优化。发现最低能量异构体涉及质子转移以生成 H(3)O(+) 和 OH 自由基，与包含半键合肼样片段 (H(2)O–OH(2)) 的异构体相比，这些异构体更稳定，计算出的红外光谱与实验数据一致。对于 (H(2)O)(9)(+)，讨论了观察到的新结构模式，其中包括质子转移以形成 H(3)O(+) 和 OH，但 OH 自由基与另一个水分子参与半键合。
