Sarmah Kangkan, Kalita Amlan J, Purkayastha Siddhartha K, Guha Ankur K
Advanced Computational Chemistry Centre, Cotton University Panbazar, Guwahati, Assam, INDIA-, 781001.
Angew Chem Int Ed Engl. 2024 Mar 22;63(13):e202318741. doi: 10.1002/anie.202318741. Epub 2024 Feb 19.
Planar hypercoordination has sparkled interest among the researchers from last few decades. Most of the elements in the Periodic Table have shown this remarkable structural feature. However, the smallest element, hydrogen, is missing in the list. No evidence is there in the literature. Herein, we introduce the first planar pentacoordinate hydrogen atom (ppH) in the global minimum geometry of Li H cluster. Bonding analysis indicates that the central hydrogen atom is stabilized by multicentre bonding with five surrounding Li atoms. Natural charge analysis reveals that the central hydrogen is acting like a hydride which is strongly attracted by the positively charged surrounding lithium centres. The ppH structure is stabilized by strong electrostatic attraction as well as extensive multicentre bonding. Aromaticity has no role to play here. The cluster is dynamically stable and is expected to be detected in gas phase.
在过去几十年里，平面超配位引起了研究人员的兴趣。元素周期表中的大多数元素都表现出这种显著的结构特征。然而，列表中缺少最小的元素氢。文献中没有相关证据。在此，我们在LiH簇的全局最小几何结构中引入了第一个平面五配位氢原子（ppH）。键合分析表明，中心氢原子通过与五个周围锂原子的多中心键合而稳定。自然电荷分析表明，中心氢的行为类似于氢化物，被带正电的周围锂中心强烈吸引。ppH结构通过强静电吸引以及广泛的多中心键合而稳定。芳香性在这里不起作用。该簇在动力学上是稳定的，有望在气相中被检测到。
