On the stability of cationic complexes of neon with helium - solving an experimental discrepancy
On the stability of cationic complexes of neon with helium - solving an experimental discrepancy
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DOI：
10.1039/c3cp52550c
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发表时间：
2013-01-01
影响因子：
3.3
通讯作者：
Echt, Olof
中科院分区：
文献类型：
--
作者：
Bartl, Peter;Denifl, Stephan;Echt, Olof
氦纳米液滴掺杂有氖并被电子电离。HenNex+的离子丰度的大小依赖性，在高分辨率质谱中确定，推导出含有多达7个氖原子和几十个氦原子的复合物。从丰度分布的异常推断出特别稳定的离子。HenNe+系列中n = 11和13处的两个明显异常证实了Kojima等人[T. M. Kojima等人，Z.，1992，22，645]。这与先前发表的掺杂氦滴的光谱不一致，它没有揭示任何丰度异常[T。Ruchti等人，J. Chem. Phys.，1998，109，10679-10687; C. A. Brindle等人，J. Chem. Phys.，2005，123，064312]，最有可能是由于有限的质量分辨率，这排除了对来自具有相同标称质量的不同离子的贡献的明确分析。然而，迄今为止报道的HenNe+的计算解离能与目前的数据不相关，可能是因为在正确处理线性，不对称的[He-Ne-He]（+）离子核心的HenNe+的挑战。在HenNex+（x > 1）的分布中发现的异常，包括在He 12 Ne 2+和He 14 Ne 2+的显著异常，可能有助于更好地理解Ne+和Ne-x（+）在氦中的溶剂化。
Helium nanodroplets are doped with neon and ionized by electrons. The size-dependence of the ion abundance of HenNex+, identified in high-resolution mass spectra, is deduced for complexes containing up to seven neon atoms and dozens of helium atoms. Particularly stable ions are inferred from anomalies in the abundance distributions. Two pronounced anomalies at n = 11 and 13 in the HenNe+ series confirm drift-tube data reported by Kojima et al. [T. M. Kojima et al., Z. Phys. D, 1992, 22, 645]. The discrepancy with previously published spectra of neon-doped helium droplets, which did not reveal any abundance anomalies [T. Ruchti et al., J. Chem. Phys., 1998, 109, 10679-10687; C. A. Brindle et al., J. Chem. Phys., 2005, 123, 064312], is most likely due to limited mass resolution, which precluded unambiguous analysis of contributions from different ions with identical nominal mass. However, calculated dissociation energies of HenNe+ reported so far do not correlate with the present data, possibly because of challenges in correctly treating the linear, asymmetric [He-Ne-He](+) ionic core in HenNe+. Anomalies identified in the distributions of HenNex+ for x > 1, including prominent ones at He12Ne2+ and He14Ne2+, may help to better understand solvation of Ne+ and Ne-x(+) in helium.