Herr Jonathan D, Talbot Justin, Steele Ryan P
Henry Eyring Center for Theoretical Chemistry, Thatcher Building for Biological and Biophysical Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112, United States.
J Phys Chem A. 2015 Jan 29;119(4):752-66. doi: 10.1021/jp509698y. Epub 2015 Jan 21.
Ionized water clusters serve as a model of water-splitting chemistry for energetic purposes, as well as postradiolytic events in condensed-phase systems. Structures, properties, and relative energies are presented for oxidized water clusters, (H2O)n=1-5(+), using equation-of-motion coupled-cluster theory approaches. In small clusters, an ion-radical contact pair OH···H3O+ is known to form upon ionization. The transition from n = 4 to n = 5 molecules in the cluster, however, is found to demarcate a size regime in which a propensity for the ion and radical to separate exists. This trend is consistent with recent experimental vibrational analyses. Decomposition of the cluster energetics reveals that preferential solvation of the hydronium cation by water serves as the dominant driving force for this pair separation, which should persist in larger clusters and bulk water ionization.
离子化水团簇作为用于能量目的的水分解化学模型，以及凝聚相系统中的辐解后事件。使用运动方程耦合簇理论方法给出了氧化水团簇(H2O)n=1-5(+)的结构、性质和相对能量。在小团簇中，已知电离时会形成离子-自由基接触对OH···H3O+。然而，发现团簇中从n = 4到n = 5个分子的转变划定了一个离子和自由基有分离倾向的尺寸范围。这一趋势与最近的实验振动分析一致。团簇能量学的分解表明，水对水合氢离子的优先溶剂化是这种对分离的主要驱动力，这种驱动力应该在更大的团簇和本体水电离中持续存在。
