Silvi Bernard, Alikhani Esmaïl, Ratajczak Henryk
Sorbonne Universités, UPMC, Univ Paris 06, UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005, Paris Cedex 05, France.
Sorbonne Universités, UPMC, Univ Paris 06, MONARIS, UMR 8233, 4 place Jussieu, F-75005, Paris Cedex 05, France.
J Mol Model. 2020 Feb 27;26(3):62. doi: 10.1007/s00894-019-4283-1.
The concept of secondary bond covers a wide range of non-covalent interactions involving an acceptor (or electrophilic) molecule and an electron donor (or nucleophilic) one. It involves triel, tetrel, pnictogen, chalcogen, halogen, and aerogen bonds as well as hydrogen bonds. Such interactions yield complexes in which the internuclear distance of the electrophilic and nucleophilic centers is intermediate between the sums of the covalent and van der Waals radii of these atoms. These complexes can be considered as precursors of hypothetical nucleophilic substitution or addition reactions. As a consequence of the least motion principle, in the complex, the arrangement of the ligands around the electrophilic center should look like that of the hypothetical transition state or addition product. In a same fashion, the geometry around the nucleophilic center is determined by the location of the lone pair or of the bond involved in the interaction. In this picture of secondary bonding, the structure of the valence shell of the electrophilic atoms determines the geometry of the complex rather than the group to which belongs the elemental atom. The reorganization of the complexes in terms of the arrangement of the bonding and non-bonding electronic domains around the electrophilic center enables to rationalize the geometries in a systematic fashion. A set of VSEPR inspired rules enabling the building up of secondary bonded isomers are proposed and checked by quantum chemical calculations performed on representative test systems of the AXE type. Graphical Abstract An example of secondary interaction: FClO[Formula: see text].
次级键的概念涵盖了广泛的非共价相互作用，涉及一个受体（或亲电）分子和一个电子供体（或亲核）分子。它包括三卤键、四卤键、氮键、氧键、卤键和气键以及氢键。这种相互作用产生的复合物中，亲电中心和亲核中心的核间距介于这些原子的共价半径和范德华半径之和之间。这些复合物可被视为假设的亲核取代或加成反应的前体。根据最小移动原理，在复合物中，亲电中心周围配体的排列应类似于假设的过渡态或加成产物。同样，亲核中心周围的几何形状由相互作用中涉及的孤对电子或键的位置决定。在这种次级键合的情况中，亲电原子价壳层的结构决定了复合物的几何形状，而非元素原子所属的基团。根据亲电中心周围键合和非键合电子域的排列对复合物进行重组，能够以系统的方式使几何形状合理化。提出了一组受价层电子对互斥理论启发的规则，用于构建次级键合异构体，并通过对AXE型代表性测试体系进行量子化学计算来检验。图形摘要：次级相互作用的一个例子：FClO[化学式：见原文]
