Sodium cation-templated synthesis of an ion-pair binding heteroditopic [2]catenane

A novel method utilising sodium cation templation between a pyridinium bridged calix[4]diquinone macrocycle and a pyridine-N-oxide functionalised macrocycle precursor motif is used for the construction of a mechanically interlocked ion-pair binding [2]catenane. The heteroditopic [2]catenane binding mode is elucidated by single-crystal X-ray crystallography with the alkali–metal sodium cation-chloride halide-anion bound in an unprecedented ‘macrocycle separated’ ion-pair configuration.