Controlled Hydrogen‐Bond Breaking in a Rotaxane by Discrete Solvation

Abstract

Controlling a molecular brake: Binding interactions between the thread and the macrocycle of a [2]rotaxane can be tuned in a quasi-continuous manner by adding hydrogen-bond-forming solvent molecules one at a time to an isolated [2]rotaxane molecule. Conformational changes that detach the thread from the macrocycle can be induced controllably, and the system resembles a molecular version of applying and releasing a brake.