Vermeeren Pascal, Wolters Lando P, Paragi Gábor, Fonseca Guerra Célia
Department of Theoretical Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands.
MTA-SZTE Biomimetic Systems Research Group, Eötvös Loránd Research Network (ELKH), Dóm tér 8, 6720, Szeged, Hungary.
Chempluschem. 2021 Jun;86(6):812-819. doi: 10.1002/cplu.202100093. Epub 2021 May 6.
Cooperative properties of halogen bonds were investigated with computational experiments based on dispersion-corrected relativistic density functional theory. The bonding mechanism in linear chains of cyanogen halide (X-CN), halocyanoacetylene (X-CC-CN), and 4-halobenzonitrile (X-C H -CN) were examined for X = H, Cl, Br, and I. Our energy decomposition and Kohn-Sham molecular-orbital analyses revealed the bonding mechanism of the studied systems. Cyanogen halide and halocyanoacetylene chains possess an extra stabilizing effect with increasing chain size, whereas the 4-halobenzonitrile chains do not. This cooperativity can be traced back to charge separation within the σ-electronic system by charge-transfer between the lone-pair orbital of the nitrogen (σ ) on one unit and the acceptor orbital of the C-X (σ* ) on the adjacent unit. As such, the HOMO-LUMO gap in the σ-system decreases, and the cooperativity increases with chain length revealing the similarity in the bonding mechanisms of hydrogen and halogen bonds.
基于色散校正的相对论密度泛函理论，通过计算实验研究了卤键的协同性质。研究了X = H、Cl、Br和I时，卤化氰（X-CN）、卤代氰乙炔（X-CC-CN）和4-卤代苯腈（X-C₆H₅-CN）线性链中的键合机制。我们的能量分解和Kohn-Sham分子轨道分析揭示了所研究体系的键合机制。卤化氰和卤代氰乙炔链随着链长增加具有额外的稳定作用，而4-卤代苯腈链则没有。这种协同性可追溯到σ电子体系内通过一个单元上氮的孤对轨道（σ）与相邻单元上C-X的受体轨道（σ*）之间的电荷转移而产生的电荷分离。因此，σ体系中的HOMO-LUMO能隙减小，协同性随链长增加，揭示了氢键和卤键键合机制的相似性。
