rotaxanes

https://doi.org/10.1351/goldbook.R05416
Molecules in which a ring encloses another, rod-like molecule having end groups too large to pass through the ring opening, and thus holds the rod-like molecule in position without covalent bonding.
R05416.png
See:
catenanes
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1364 [Terms] [Paper]