Rotaxanes as new architectures for photoinduced electron transfer and molecular motions

Rotaxanes are molecular architectures ideally suited for building integrate d, multicomponent modular systems, displaying novel chemical and physical p roperties. In this new field of functional rotaxanes, those incorporating t ransition metals, which are incidentally used as synthetic templates, are p articularly attractive for their photophysical and electronic properties as well as their dynamic behaviour. It is believed that they will provide, in the future, the basic elements for constructing nanoscale machines and mot ors.