Polyrotaxanes: Molecular composites derived by physical linkage of cyclic and linear species

Molecular composites consisting of cyclic molecules whose cavities have been pierced by linear molecules (see Figure) were discussed as early as 1910. However, recently interest in these molecules, which are known as rotaxanes, and their polymeric derivatives has intensified due to their unique property profiles which cannot be compared with those their components. Progress with rotaxanes and related compounds such as catenanes is reviewed. magnified image