Self assembled cages with mechanically interlocked cucurbiturils

We report (bis)aniline 4 which contains a central viologen and its self-assembly with aldehyde 5 and Fe(OTf)₂ to yield tetrahedron 6. Complexation of 4 with CB[7] in the form of CB[7]•4•2PF₆ allows the preparation of assembly 7 which contains 1.95 mechanically interlocked CB[7] units. Assemblies 6 and 7 are hydrolytically unstable due to their imine linkages. Redesign of our system with water stable 2,2ʹ-bipyridine end groups was realised in the form of ligands 11 and 16. Self-assembly of 11 with Fe(NTf₂)₂ gave tetrahedral MOP 12. Isomeric ligand 16 underwent self-assembly with Fe(OTf)₂ to give cube 17. Precomplexation of ligands 11 and 16 with CB[7] gave the acetonitrile soluble CB[7]•11•2PF₆ and CB[7]•16•2PF₆ complexes. Self-assembly of CB[7]•11•2PF₆ with Fe(OTf)₂ gave tetrahedron 13 which contains 1.8 mechanically interlocked CB[7] units. Self-assembly of CB[7]•16•2PF₆ with Fe(OTf)₂ gave cube 13 which contains 6.59 interlocked CB[7] units.