Rotaxane- and Catenane-based Molecular Machines and Motors

The concept of (macroscopic) machine can be extended to the molecular level. A molecular machine can be defined as an assembly of a discrete number of molecular components (i.e., a supramolecular system) in which the component parts can display changes in their relative positions as a result of some external stimulus. Rotaxanes and catenanes are promising systems for the construction of artificial molecular machines. The design, synthesis and investigation of chemical systems able to function as molecular machines and motors is of interest not only for basic research, but also for the growth of nanoscience and the development of nanotechnology. A few examples of molecular machines taken from our own research will be illustrated.