Song Junjie, Wang Mengyang, Xu Xiaocheng, Shao Qinghao, Zhao Ying, Zhang Guiqiu, Sun Nan
Key Laboratory of Molecular and Nano Probes, Ministry of Education, College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China.
Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, China.
Molecules. 2023 Aug 24;28(17):6212. doi: 10.3390/molecules28176212.
Charge-shift (CS) bonding is a new bonding paradigm in the field of chemical bonds. Our recent study has revealed that certain Cu/Ag/Au-bonds display both CS bonding and ω-bonding characters. In this investigation, we extend our study to halogen bonding. Our focus is on scrutinizing the CS bonding in halogen-bonded BXY (B is a small Lewis base HO or NH; X and Y are halogen atoms) complexes by using natural bond orbital (NBO) analysis, natural resonance theory (NRT), and atoms in molecules (AIM) methods. The primary objective is to establish a connection between halogen bonding (B-X) in BXY and CS bonding in free XY (di-halogens). The calculations indicate that the studied BXY can be classified into two types. One type with a weak halogen bond shows closed-shell interaction. The other type with a stronger B-X interaction exhibits both CS bonding and ω-bonding characters (as seen in NHClF, NHBrF, and NHIF). Another interesting finding is a novel propensity that the CS bonding in free XY tends to carry over the halogen bonding in BXY, and the same propensity is found in Cu/Ag/Au ω-bonded species. The present study may offer an approach to probe CS bonding in many more 3c/4e ω-bonded molecules.
电荷转移（CS）键合是化学键领域中的一种新的键合模式。我们最近的研究表明，某些铜/银/金键兼具CS键合和ω键合特征。在本研究中，我们将研究扩展到卤键。我们的重点是通过使用自然键轨道（NBO）分析、自然共振理论（NRT）和分子中的原子（AIM）方法，仔细研究卤键合的BXY（B是小的路易斯碱HO或NH；X和Y是卤原子）配合物中的CS键合。主要目的是在BXY中的卤键（B-X）和游离XY（双卤化物）中的CS键合之间建立联系。计算结果表明，所研究的BXY可分为两类。一类卤键较弱，表现为闭壳层相互作用。另一类B-X相互作用较强，兼具CS键合和ω键合特征（如在NHClF、NHBrF和NHIF中所见）。另一个有趣的发现是一种新的倾向，即游离XY中的CS键合倾向于延续到BXY中的卤键合，并且在铜/银/金ω键合物种中也发现了相同的倾向。本研究可能为探索更多3c/4eω键合分子中的CS键合提供一种方法。
