Guest-length driven high fidelity self-sorting in supramolecular capsule formation of calix[5]arenes in water

A four component system consisting of two water-soluble calix[5]arenes (1 and 2) with differently substituted upper-rims and two α,ω-alkanediyldiammonium ions of different lengths (NC8N and NC10N) was found to assemble in a high-fidelity fashion providing exclusively the two homocalixarene capsules 1⊃NC8N⊂1 and 2⊃NC10N⊂2, irrespective of the order of guest addition. When the longer linker (NC10N) was left out from the mixture altogether, however, 1⊃NC8N⊂2 heterocapsules were formed.