Unveiling the Hidden Movements in the Shuttling of Rotaxanes  

作　　者：GUO Yichang FU Haohao SHAO Xueguang CAI Wensheng 

机构地区：[1]Research Center for Analytical Sciences,College cf Chemistry,Tianjin Key Laboratory of Biosensing and Molecular Recognition,Nankai University,Tianjin 300071,P.R.China [2]State Key Laboratory of Medicinal Chemical Biology,Tianjin 300071,P.R.China

出　　处：《Chemical Research in Chinese Universities》2020年第5期748-754,共7页高等学校化学研究（英文版）

基　　金：Supported by the National Natural Science Foundation of China(No.21773125);the Fundamental Research Funds for the Central Universities,China(No.63191743);the Natural Science Foundation of Tianjin,China(No.18JCYBJC2O5OO);the China Postdoctoral Science Foundation(No.bs6619012).

摘　　要：Movements in molecular machines are usually diverse and coupled,but some of them are often implicit and hard to be observed in experiments.In the present work,the two-or three-dimensional free-energy landscapes characterizing the coupled shutthng and other movements of a series of pH-triggered rotaxanes composed of a crown ether and an H-shaped axle with distinct number of phenyl rings(n=1-3)have been explored.The results show that although the calculated free-energy barriers against shutthng in the rotaxanes(n=2 and 3)change slightly,the move-ments coupled with the shutthng vary significantly with the axle length.At high pH,the shutthng in the rotaxane of n=2 is coupled with the isomerization of the wheel,while the shutthng in the one of n=3 is accompanied by both the isomerization and the rotation of the macrocycle.In addition,the crown ether imdenvent greater conlomiational change during shutthng at low pH compared to that at high pH.These results indicate that disentangling the coupled movements is important to reveal the underlying molecular mechanism of the shutthng.

关 键 词：ROTAXANE Molecular machine Molecular movement Free-eiiergy landscape 

分 类 号：O62[理学—有机化学]