Faculty of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warsaw, Poland.
Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30-239 Cracow, Poland.
Molecules. 2022 Nov 16;27(22):7938. doi: 10.3390/molecules27227938.
Intermolecular complexes with calixarenes are intriguing because of multiple possibilities of noncovalent binding for both polar and nonpolar molecules, including docking in the calixarene cavity. In this contribution calix[6]arenes interacting with amino acids are studied with an additional aim to show that tools such as symmetry-adapted perturbation theory (SAPT), functional-group SAPT (F-SAPT), and systematic molecular fragmentation (SMF) methods may provide explanations for different numbers of noncovalent bonds and of their varying strength for various calixarene conformers and guest molecules. The partitioning of the interaction energy provides an easy way to identify hydrogen bonds, including those with unconventional hydrogen acceptors, as well as other noncovalent bonds, and to find repulsive destabilizing interactions between functional groups. Various other features can be explained by energy partitioning, such as the red shift of an IR stretching frequency for some hydroxy groups, which arises from their attraction to the phenyl ring of calixarene. Pairs of hydrogen bonds and other noncovalent bonds of similar magnitude found by F-SAPT explain an increase in the stability of both inclusion and outer complexes.
由于具有多种非共价键合的可能性，包括在杯芳烃空腔中的对接，杯芳烃的分子间复合物非常有趣。本研究用氨基酸与杯[6]芳烃相互作用，目的是展示对称性自适应微扰理论（SAPT）、功能基团 SAPT（F-SAPT）和系统分子断裂（SMF）等方法可以解释不同数量的非共价键以及它们对不同构象的杯芳烃和客体分子的强度变化。相互作用能的划分提供了一种简单的方法，可以识别氢键，包括具有非常规氢键受体的氢键，以及其他非共价键，并找到功能基团之间的排斥失稳相互作用。通过能量划分可以解释其他各种特征，例如一些羟基的 IR 伸缩频率红移，这是由于它们被吸引到杯芳烃的苯基环上。F-SAPT 发现的氢键对和其他类似大小的非共价键对可以解释内包和外配合物稳定性的增加。
