ABSTRACT
The most common classes of interlocked molecules are catenanes and rotaxanes1 derived from the Latin catena, rota, and axis (meaning chain, wheel, and axle, respectively). As depicted in Figure 10.1, a catenane is composed of interlocking rings (a). A rotaxane contains a macrocyclic component looped around an axle, held in place by two bulky stoppers (b). A related supramolecular structure is the pseudorotaxane (c)—an inclusion complex in which an axle without stoppers resides inside a macrocycle. This interpenetrated, but not interlocked, assembly is often a precursor to catenanes and rotaxanes.
