Design Considerations for the Group 15 Elements: The Pnictogen···π Interaction As a Complementary Component in Supramolecular Assembly Design

An exhaustive structural survey was analyzed in combination with new structural reports on pnictogen···π interactions. The Cambridge Structural Database was searched for examples of pnictogen atoms (As, Sb, and Bi) that lie within the sum of their van der Waals radii with an arene ring. The results were analyzed, and it was concluded that the interaction distance is shorter for the heavier pnictogens due to the increasingly diffuse nature of the lone pair of electrons on the atom. A weak correlation between the distance and the angle of the interaction was found, implying that the interaction is partially covalent in nature but is primarily a dispersion interaction. These arene···π interactions can be used as driving forces for supramolecular assembly, and the crystal structures of two new arsenic-containing assemblies are presented. The combined analysis of these structures and the structural survey suggest that our supramolecular design strategy can be fine-tuned to take advantage of the pnictogen···π interaction.

本研究结合针对氮族元素（pnictogen）···π相互作用的最新结构报道，对一项系统性结构普查结果展开了综合分析。我们针对剑桥结构数据库（Cambridge Structural Database）开展检索，筛选出氮族元素原子（砷As、锑Sb、铋Bi）与芳烃环间距处于二者范德华半径之和范围内的案例。分析结果显示，原子量更大的氮族元素其相互作用距离更短，这源于该类原子上孤对电子的弥散程度随原子序数提升而不断增强。研究同时发现，相互作用距离与作用角度之间存在弱相关性，这表明该相互作用本质上兼具部分共价性，但主要仍属于色散相互作用。这类芳烃···π相互作用可作为超分子组装的核心驱动力，本文同时报道了两种全新含砷超分子组装体的晶体结构。通过对上述晶体结构与前期结构普查结果的综合分析，本研究证实可通过微调超分子设计策略，充分利用氮族元素···π相互作用。