Hybrid organic–inorganic rotaxanes and molecular shuttles

Rotaxanes, in which ring-shaped subunits encircle the 'axles' of molecular dumb-bells, have been mooted as possible components of molecular machines. To date, most rotaxanes are organic, but David Leigh and colleagues now report hybrid rotaxanes, which are expected to offer a far wider range of useful physical properties to molecular engineers than purely organic rotaxanes.