Department of Chemistry and Biochemistry, University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA.
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Angew Chem Int Ed Engl. 2021 Feb 15;60(7):3685-3692. doi: 10.1002/anie.202012262. Epub 2020 Dec 21.
Proximal noncovalent forces are commonplace in natural systems and understanding the consequences of their juxtaposition is critical. This paper experimentally quantifies for the first time a Hydrogen Bond-Enhanced Halogen Bond (HBeXB) without the complexities of protein structure or preorganization. An HBeXB is a halogen bond that has been strengthened when the halogen donor simultaneously accepts a hydrogen bond. Our theoretical studies suggest that electron-rich halogen bond donors are strengthened most by an adjacent hydrogen bond. Furthermore, stronger hydrogen bond donors enhance the halogen bond the most. X-ray crystal structures of halide complexes (X =Br , I ) reveal that HBeXBs produce shorter halogen bonds than non-hydrogen bond analogues. F NMR titrations with chloride highlight that the HBeXB analogue exhibits stronger binding. Together, these results form the foundation for future studies concerning hydrogen bonds and halogen bonds in close proximity.
在自然体系中，近端非共价相互作用力很常见，理解它们并置的后果至关重要。本文首次通过实验定量研究了没有蛋白质结构或预组织复杂性的氢键增强卤键（HBeXB）。HBeXB 是一种卤键，当卤原子供体同时接受氢键时，该卤键得到增强。我们的理论研究表明，富电子的卤键供体受相邻氢键的增强作用最大。此外，更强的氢键供体增强卤键的作用最大。卤化物配合物（X=Br，I）的 X 射线晶体结构表明，HBeXB 产生的卤键比非氢键类似物更短。与氯化物的 19 F NMR 滴定实验表明，HBeXB 类似物表现出更强的结合能力。这些结果为未来关于近距离氢键和卤键的研究奠定了基础。
