Fig. 21. Stoddart's stereochemical Rubik's cube 54 that exists as a complex mixture of diastereomers in slow exchange as a result of the mechanical bond.63 (a) Structures of parent macrocycles 52, 53 and catenane 54. (b) Conformational stereoisomers of macrocycles 52 and 53. (c) Stereoisomerism in catenane 54 (enantiomers of each diastereomer not shown). Counter ions omitted for clarity.
