Colour coding the co-conformations of a [2]rotaxane flip-switch

摘要

Fine-tuning the charge transfer chromophores in a series of [2]rotaxane flip-switches yields a unique optical signal (purple colour) for one of the interactions allowing for facile determination of the position of the flip-switch equilibrium. A mechanically interlocked molecule (MIM) such as a [2]rotaxane can operate as a molecular switch if two different recognition sites are available on the axle for recognition and binding of the macrocyclic wheel.1 In this type of [2]rotaxane molecular shuttle, the two states are translational co-conformers related by the relative positioning of the macrocycle along the length of the axle.2 Similarly, we reported the concept of a molecular flip-switch that operates at a single recognition site on