Five additional macrocycles that allow Na+ ion-templated threading of guest units featuring a single urea or amide functionality.

Five analogues of the macrocycle BPX26C6 are also capable of recognizing single urea and/or amide functionalities in the presence of templating Na(+) ions. We have unambiguously confirmed the formation of such [2]pseudorotaxane complexes in solution through syntheses of the corresponding [2]rotaxanes.

Na+ ion templated threading of oligo(ethylene glycol) chains through BPX26C6 allows synthesis of [2]rotaxanes under solvent-free conditions.

Threading of di-, tri-, and tetra(ethylene glycol) through the macrocycle BPX26C6 in the presence of templating Na(+) ions was proven by the synthesis of the corresponding [2]rotaxanes under solvent-free conditions. Among them, a [2]rotaxane featuring both tetra(ethylene glycol) and carbamate stations behaves as a molecular switch that can be controlled reversibly through the application of the KTFPB/[2.2.2]cryptand reagent pair.