Guo Jin-Chang, Feng Lin-Yan, Zhang Xiao-Ying, Zhai Hua-Jin
Institute of Materials Science and Department of Chemistry, Xinzhou Teachers' University , Xinzhou 034000, Shanxi, China.
Nanocluster Laboratory, Institute of Molecular Science, Shanxi University , Taiyuan 030006, China.
J Phys Chem A. 2018 Feb 1;122(4):1138-1145. doi: 10.1021/acs.jpca.7b11789. Epub 2018 Jan 19.
We report on the computational design of star-like CBeAu cluster with planar pentacoordinate carbon (ppC), which is also classified as a superalkali cation. Relevant isovalent CBeAu (n = 2-4), BBeAu, and NBeAu clusters with ppC/B/N are studied as well. Global-minimum structures of the clusters are established via computer global searches. The species feature a pentacoordinate pentagonal XBe (X = C, B, N) core, with Au occupying outer bridging positions. Molecular dynamics simulations indicate that they are dynamically stable. Bonding analysis reveals 3-fold (π and σ) aromaticity in CBeAu, a key concept that overrides the 18-electron rule and should be applicable for (or help revisit existing models of) other planar hypercoordinate systems. Vertical electron affinities of CBeAu and its lighter counterparts (CBeCu and CBeAg) are calculated to be unusually low, which are below 3.89 eV, the smallest atomic ionization potential of any element in the periodic table. Thus, these three clusters belong to superalkali cations. The merge of ppC and superalkali characters makes them unique chemical species.
我们报道了具有平面五配位碳（ppC）的星状CBeAu簇的计算设计，该簇也被归类为超碱阳离子。还研究了具有ppC/B/N的相关等电子CBeAu（n = 2 - 4）、BBeAu和NBeAu簇。通过计算机全局搜索确定了这些簇的全局最小结构。这些物种具有一个五配位的五角形XBe（X = C、B、N）核心，Au占据外部桥接位置。分子动力学模拟表明它们是动态稳定的。键合分析揭示了CBeAu中的三重（π和σ）芳香性，这一关键概念超越了18电子规则，并且应该适用于（或有助于重新审视）其他平面超配位系统的现有模型。计算得出CBeAu及其较轻的对应物（CBeCu和CBeAg）的垂直电子亲和能异常低，低于3.89 eV，这是元素周期表中任何元素的最小原子电离能。因此，这三个簇属于超碱阳离子。ppC和超碱特性的融合使它们成为独特的化学物种。
