Self-Sorting via Macrocyclization by External Templation in Water

Here, by condensing each of two bisformyl precursors with the corresponding bishydrazide partner in water, two ultrasized macrocycles could be self-assembled. One was self-assembled within the cavity of cucurbit[8]uril (CB[8]) acting as an external template, forming a ring-in-ring complex. The other requires the presence of both CB[10] and a π-electron-rich guest as an external/internal template, thus forming a ternary complex "Russian doll". When all seven precursors were combined in water, self-sorting occurred without forming hybridized products.