rotaxane
/rə(ʊ)ˈtakseɪn/Chemistry
noun
Any compound having a molecular structure in which a chain of atoms is threaded through a ring and, though not chemically bonded to the ring, is mechanically constrained in position by the ring's structure.
Origin
1960s; earliest use found in Chemical Abstracts. From German Rotaxan (G. Schill & H. Zollenkopf 1967, in Nachrichten aus Chemical u. Technik 15 149/2; from classical Latin rota wheel + ax- (in axis) + German -an), with remodelling of the ending after -ane.