Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Chandigarh, India.
Phys Chem Chem Phys. 2020 May 28;22(20):11558-11566. doi: 10.1039/d0cp00351d. Epub 2020 May 12.
We demonstrate herein a computational study probing the influence of metalloporphyrins on intermolecular halogen bonding (XB) during supramolecular self-assembly. The results demonstrate that porphyrin aromatic rings can activate or deactivate halogen bonding interactions, especially those on axial ligands, and further influence the preference type of halogen···halogen bonding during the supramolecular self-assembly. Calculations show that the halogen atom present at the equatorial position has a higher sigma hole potential (V) than that at the axial position. The computational analysis and our observations from the X-ray structure analysis are in good agreement. From structural analysis it is clear that equatorial halogen atoms prefer to participate in Type-II XB interactions whereas the axial halogen atoms either participate in Type-I XB interaction or reluctant to participate in XB interactions due to the decrease of their sigma hole potential. Thus, we demonstrate, herein, for the first time a computational study probing the direct influence of the porphyrin's ring current on the sigma hole potential (V) of the halogen atoms and subsequently the effects of the supramolecular self-assembly.
我们在此展示了一项计算研究，探讨金属卟啉对超分子自组装过程中分子间卤键（XB）的影响。结果表明，卟啉芳环可以激活或失活卤键相互作用，特别是轴向配体上的卤键相互作用，并进一步影响超分子自组装过程中卤···卤键的优先类型。计算表明，处于赤道位置的卤原子具有比轴向位置更高的 sigma 空穴势能（V）。计算分析与我们从 X 射线结构分析中观察到的结果非常一致。从结构分析可以清楚地看出，赤道卤原子更喜欢参与 II 型 XB 相互作用，而轴向卤原子由于 sigma 空穴势能降低，要么参与 I 型 XB 相互作用，要么不愿意参与 XB 相互作用。因此，我们首次在此展示了一项计算研究，探讨卟啉环电流对卤原子 sigma 空穴势能（V）的直接影响，以及随后对超分子自组装的影响。
