Institut für Physikalische Chemie, Universität Göttingen, Germany.
J Chem Phys. 2010 Jun 14;132(22):221102. doi: 10.1063/1.3439393.
A new class of sodium-water clusters with a low lying ionization potential (IP) is characterized by their photoionization spectra in molecular beam experiments. This implies that Na(H(2)O)(n) clusters coexist for n>or=15 in two forms of significant abundances being distinguished by their IPs of approximately 2.8 and approximately 3.2 eV. A tentative quantum chemical characterization was achieved by simulating ionization spectra for selected cluster sizes using an ab initio molecular dynamics approach. Experiment and theory suggest that the Na(+)-e(-) distance is significantly larger in the clusters with the lower IP. This indicates that the solvated electron in Na(H(2)O)(n) clusters very probably forms with the Na(+) counterion both a solvent separated and a contact ion pair.
新型低电离势（IP）的钠离子-水团簇的特征在于其在分子束实验中的光致电离光谱。这意味着 Na(H(2)O)(n) 团簇在 n≥15 时以两种形式共存，其 IP 分别约为 2.8 和 3.2 eV。通过使用从头算分子动力学方法模拟选定簇大小的电离光谱，实现了初步的量子化学特征化。实验和理论都表明，在具有较低 IP 的团簇中，Na(+)-e(-)距离明显更大。这表明 Na(H(2)O)(n) 团簇中的溶剂化电子很可能与 Na(+)反离子形成溶剂分离和接触离子对。
