Exploring the self-assembly of polar dimeric capsules using molecular rulers.
A homologous series of N,N,N',N'-tetramethylalkyl-N,N'-dioxides is used to probe the level of guest induced fit attainable in the assembly of a dimeric capsule based on tetraurea benzyl calix[4]pyrrole components. A sensible enhancement of the capsule's volume was observed in response to guest size for n = 2, 3, and 4. In turn, larger guests adopted folded conformations to adapt to the capsule's dimensions.