Yuan Yongna, Mills Matthew J L, Li Fuyang, Du Yuhong, Wei Jiaxuan, Su Wei
School of Information Science & Engineering, Lanzhou University, No.222 South Tianshui Road, Lanzhou, 730000, China.
3M Corporate Research Analytical Laboratory, Saint Paul, MN, 55114, USA.
J Mol Model. 2020 Nov 4;26(11):331. doi: 10.1007/s00894-020-04591-2.
A series of interatomic interactions interpretable as halogen bonds involving I…I, I…O, and I…C(π), as well as the noncovalent interactions I…H and O…O, were observed in the crystal structures of trans-1,2-diiodoolefins dimers according to ab initio calculations and the quantum theory of "atoms in molecules" (QTAIM) method. The interplay between each type of halogen bond and other noncovalent interactions was studied systematically in terms of bond length, electrostatic potential, and interaction energy, which are calculated via ab initio methods at the B3LYP-D3/6-311++G(d,p) and B3LYP-D3/def2-TZVP levels of theory. Characteristics and nature of the halogen bonds and other noncovalent interactions, including the topological properties of the electron density, the charge transfer, and their strengthening or weakening, were analyzed by means of both QTAIM and "natural bond order" (NBO). These computational methods provide additional insight into observed intermolecular interactions and are utilized to explain the differences seen in the crystal structures. Graphical abstract The contour map presents the regions of electronic concentration and depletion along each bond in one dimer. The blue points denote the BCPs. The blue lines denote positive Laplacian of electron density, which indicate the ionic interactions, van der Waals or intermolecular interactions, and the red lines denote negative Laplacian of electron density which indicate the covalent bonds.
根据从头算计算和“分子中的原子”量子理论（QTAIM）方法，在反式-1,2-二碘代烯烃二聚体的晶体结构中观察到了一系列可解释为卤键的原子间相互作用，包括I…I、I…O和I…C（π），以及非共价相互作用I…H和O…O。通过在B3LYP-D3/6-311++G（d,p）和B3LYP-D3/def2-TZVP理论水平上的从头算方法，系统地研究了每种卤键与其他非共价相互作用之间在键长、静电势和相互作用能方面的相互作用。利用QTAIM和“自然键序”（NBO）分析了卤键和其他非共价相互作用的特征和本质，包括电子密度的拓扑性质、电荷转移及其增强或减弱。这些计算方法为观察到的分子间相互作用提供了额外的见解，并用于解释晶体结构中看到的差异。图形摘要等高线图展示了一个二聚体中沿每条键的电子浓度和耗尽区域。蓝色点表示键临界点（BCP）。蓝色线表示电子密度的正拉普拉斯算子，它表示离子相互作用、范德华或分子间相互作用，红色线表示电子密度的负拉普拉斯算子，它表示共价键。
