Catenanes are interlocked macrocyclic rings. It has potential applications in molecular electronics. The number of interlocked molecules is numbered n. If n is big or many smaller catenanes such as [2]catenane is linked together by a covalent bonds it is called polycatenane. A catenane is a topoisomer of its components, i.e. it is a different topological structure like DNA that has been acted on by topoisomerase.
See also
Synthesis
There are several conceptual approaches to making catenanes. One can start with a complete macrocycle and thread another chemical chain into it and link it up or one can start with non-macrocyclic precursors and hold them together while forming them into macrocycles. Some approaches result in a very low yield of catenane and other approaches give a very high yield.
Families of Catenanes
There are a number of distinct methods of holding the pre-cursors together and "closing the loop" and these give rise to different families of catenanes.
Bis-Pyridinium Catenanes
Bis-Pyridinium salts have a strong desire to form complexes with the crown ether bis-para-phenol-18-crown-6
(note:I did this chemistry a long time ago and need to check the nomenclature (chemical names) for accuracy).