Theoretical Study Of A Switchable [2]-Rotaxane

In recent years, pioneering work carried out by Sauvage, Stoddart and co-workers [1], , has focused on the development of synthetic methodologies and the characterization of catenanes and rotaxanes. Catenanes and rotaxanes are examples of interlocked molecule. Unlike classical molecular structures, they consist of two or more separate components which are mechanically connected. Catenanes consist of two or more interlocked macrocyclic rings, while rotaxanes are constituted by a macrocyclic ring trapped on a linear unit, i.e., the thread, by two bulky stoppers The submolecular units may undergo relative motions such as “circumrotation” (rotation of one ring inside the cavity of the other) and “shuttling” (linear motion along the thread), which may be addressed by external stimuli, such as photons, electrons and solvent variations. This property makes rotaxanes and catenanes prime candidates for the construction of artificial molecular-level machines and possibly for the fabrication of molecular electronic devices , attracting considerable attention from chemists, physicists, and materials scientists. Controlling the location of a macrocycle between two or more (non-) equivalent sites in a catenane or a rotaxane has already been achieved . Unfortunately, little is yet known about the mechanisms by which mechanically interlocked components move with respect to each other.