Rotaxanes synthesized through sodium-ion-templated clipping of macrocycles around nonconjugated amide and urea functionalities.

A single urea or amide functionality in a dumbbell-shaped guest can be "clipped" by a macrocycle generated from a diamine and a dialdehyde through the templating effect of a Na(+) ion (see scheme). The resulting imine-containing rotaxanes can then be reduced to allow isolation of stable amine-based rotaxanes.