He Shan, Quan Mao, Yang Liu-Pan, Au-Yeung Ho Yu, Jiang Wei
Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong Hong Kong China
Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis, Shenzhen Grubbs Institute, Southern University of Science and Technology Shenzhen 518055 China.
Chem Sci. 2024 Aug 30;15(38):15841-8. doi: 10.1039/d4sc02831g.
Conformational changes in non-covalent complexes are of fundamental importance to many chemical and biological processes. Yet, these low-energy structural changes are usually fast and difficult to monitor, which poses challenges in their detailed kinetic understanding. The correlation between kinetics and thermodynamics of the conformational change of a model supramolecular system featuring a flexible naphthocage and quaternary ammonium guests is described in this work. Guest binding initially locks the host in two major conformations, which then equilibrates over time to the more stable conformer. The overall rate of the system to attain conformational equilibrium is found to inversely correlate with the thermodynamic stability of the host-guest complexes, and hence not only can the kinetic parameters of the conformational exchange be predicted from the easily obtainable thermodynamic data, but the kinetic profile can also be rationalized by using the structural properties of the different guests.
非共价复合物中的构象变化对许多化学和生物过程至关重要。然而，这些低能量结构变化通常很快且难以监测，这给详细了解其动力学带来了挑战。本文描述了一个以柔性萘笼和季铵客体为特征的模型超分子体系构象变化的动力学与热力学之间的相关性。客体结合最初将主体锁定在两种主要构象中，随后这些构象会随时间平衡为更稳定的构象异构体。发现该体系达到构象平衡的总体速率与主客体复合物的热力学稳定性呈负相关，因此不仅可以从易于获得的热力学数据预测构象交换的动力学参数，还可以利用不同客体的结构性质来合理解释动力学曲线。
