The Lewis electron-pair bonding model: the physical background, one century later
The Lewis electron-pair bonding model: the physical background, one century later
复制标题
路易斯电子对键合模型：一个世纪后的物理背景
DOI：
10.1038/s41570-018-0052-4
复制
发表时间：
2019
影响因子：
36.3
通讯作者：
G. Frenking
中科院分区：
文献类型：
--
作者：
L. Zhao;W. H. E. Schwarz;G. Frenking
共享电子对成键模型是由吉尔伯特刘易斯在100多年前提出的。刘易斯结构是从当时的化学经验中产生的，它用经验适应的模型描述了化学现实的当代方面，而没有任何（当时未知的）量子物理基础。这一观点详细介绍了刘易斯模型的起源和历史发展，我们将其与当代量子化学中化学键的物理理解进行了对比。对过去的一些直觉上似乎合理的经典解释，尤其是两个原子共享电子以及共享电子对键和配位键的亚型，被证明是有根据的。其他一些化学教条，包括仅在两个核之间发生成键且由自旋耦合引起的概念或键能纯粹来自静电的概念，都没有那么充分的根据。我们现在知道，共价键不是由电子对的形成驱动的，而是由键合区域中共享电子的动能密度的降低驱动的，这是由原子波函数的干涉提供的。刘易斯结构仍然是描述分子结构和化学反应中的化学键合的非常有用的模型，特别是当得到量子化学的支持时。介绍了三种最常用的量子化学近似方法--价键理论、分子轨道理论和密度泛函理论。这些方法使我们了解到成键是一种充满活力的现象，从这些现象中可以推导出键长、键离解能和力常数等描述符。键合的能量来源指向键能分解分析作为阐明键合电子行为的自然工具。
The shared electron-pair bonding model was suggested by Gilbert Lewis more than 100 years ago. Emerging from the chemical experience of the time, Lewis structures described contemporary aspects of chemical reality in terms of empirically adapted models without any (then unknown) quantum physical underpinnings. This Perspective details the origins and historical development of the Lewis model, which we contrast with the physical understanding of chemical bonding in terms of contemporary quantum chemistry. Some intuitively plausible classical explanations of the past, not least of which are the sharing of electrons by two atoms and the subtypes of shared electron-pair bonding and dative bonding, turned out to be well founded. Some other chemical dogmata, including the concept that bonding occurs only between two nuclei and is caused by spin coupling or that bond energy is of purely electrostatic origin, are less well founded. We now know that covalent bonding is not driven by the formation of an electron pair but rather by the lowering of the kinetic energy density of the shared electrons in the bonding region, which is provided by the interference of the atomic wavefunctions. Lewis structures remain highly useful models for describing chemical bonding in molecular structures and chemical reactions, particularly when supported by quantum chemistry. The concepts behind the three most common quantum chemical approximations — the valence bond, molecular orbital and density functional theories — are described. These methods allow us to learn that bonding is an energetic phenomenon, from which descriptors such as bond length, bond dissociation energies and force constants are derivable. The energetic origins of bonding point to bond energy decomposition analysis as a natural tool for elucidating the actions of bonding electrons.