Hydrazide-Bearing Folda-Bonder for Modular Synthesis of π-Stacked Ring-in-Rings Complexes

Pseudostatic supramolecular preorganization coupled with dynamic covalent chemistry enables the selective construction of structurally defined ring-in-rings complexes. Cucurbit[8]uril folds a bis(acylhydrazide) into a reactive 1:1 complex that captures various aromatic dialdehydes in water, reaching a near-quantitative NMR yield (up to 97%). Single crystals can be obtained directly from post-reaction solutions without product isolation. Four related structures reveal robust cofacial π-stacking together with core-dependent dynamics and higher order packing.