Domagała Małgorzata, Lutyńska Aneta, Palusiak Marcin
Theoretical and Structural Chemistry Group, Faculty of Chemistry , University of Lodz , Pomorska 163/165 , 90-236 Lodz , Poland.
J Phys Chem A. 2018 Jun 21;122(24):5484-5492. doi: 10.1021/acs.jpca.8b03735. Epub 2018 Jun 8.
The stable model of a double (±)charge-assisted halogen bridge has been built on the basis of searches of the Crystal Structure Database. The model, investigated by DFT theory, consists of quinuclidine-like cation derivatives and a set of simple anions. These charged fragments form halogen-bonded complexes of which the energy of complexation in some cases reaches 100 kcal/mol. Even for such strong interactions, the QTAIM characteristics are similar to those of the more classic, relatively weak halogen bonds. An important effect of complexation is the charge transfer measured by means of QTAIM and NBO. It can also be supposed, on the basis of detailed structural and QTAIM analysis, that the delocalization of the charge in a quinuclidine moiety occurs through space and not necessarily along formal bonds. The analysis of only partially charged and fully neutral counterparts of a double (±)charge-assisted halogen bridge shows significantly weaker bonding, being less than 10 kcal/mol.
基于对晶体结构数据库的搜索，构建了双（±）电荷辅助卤素桥的稳定模型。该模型通过密度泛函理论（DFT）进行研究，由喹核碱样阳离子衍生物和一组简单阴离子组成。这些带电片段形成卤素键合配合物，在某些情况下其络合能达到100千卡/摩尔。即使对于如此强的相互作用，量子拓扑原子间相互作用分子理论（QTAIM）特征也与更经典、相对较弱的卤素键相似。络合的一个重要效应是通过QTAIM和自然键轨道（NBO）测量的电荷转移。基于详细的结构和QTAIM分析，还可以推测，喹核碱部分的电荷离域是通过空间发生的，不一定沿着形式键。对双（±）电荷辅助卤素桥仅部分带电和完全中性的对应物的分析表明，其键合明显较弱，小于10千卡/摩尔。
