Shaik Sason, Danovich David, Galbraith John Morrison, Braïda Benoît, Wu Wei, Hiberty Philippe C
Institute of Chemistry, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel.
Department of Chemistry, Biochemistry and Physics, Marist College, 3399 North Road, Poughkeepsie, NY, 12601, USA.
Angew Chem Int Ed Engl. 2020 Jan 13;59(3):984-1001. doi: 10.1002/anie.201910085. Epub 2019 Nov 12.
Charge-shift bonds (CSBs) constitute a new class of bonds different than covalent/polar-covalent and ionic bonds. Bonding in CSBs does not arise from either the covalent or the ionic structures of the bond, but rather from the resonance interaction between the structures. This Essay describes the reasons why the CSB family was overlooked by valence-bond pioneers and then demonstrates that the unique status of CSBs is not theory-dependent. Thus, valence bond (VB), molecular orbital (MO), and energy decomposition analysis (EDA), as well as a variety of electron density theories all show the distinction of CSBs vis-à-vis covalent and ionic bonds. Furthermore, the covalent-ionic resonance energy can be quantified from experiment, and hence has the same essential status as resonance energies of organic molecules, e.g., benzene. The Essay ends by arguing that CSBs are a distinct family of bonding, with a potential to bring about a Renaissance in the mental map of the chemical bond, and to contribute to productive chemical diversity.
电荷转移键（CSB）构成了一类新型的化学键，与共价/极性共价键和离子键不同。CSB中的键合并非源于键的共价或离子结构，而是源于这些结构之间的共振相互作用。本文阐述了价键理论先驱者忽略CSB家族的原因，然后证明了CSB的独特地位并不依赖于理论。因此，价键（VB）、分子轨道（MO）和能量分解分析（EDA）以及各种电子密度理论都表明了CSB与共价键和离子键的区别。此外，共价-离子共振能可以通过实验进行量化，因此与有机分子（如苯）的共振能具有相同的基本地位。本文最后指出，CSB是一类独特的键合方式，有可能在化学键的思维地图中引发一场复兴，并为丰富的化学多样性做出贡献。
