Coordination-driven self-organization of switchable [2]rotaxane

Abstract

A bistable porphyrin-containing [2]rotaxane is synthesized with a shuttling benzylic-amide macrocycle mechanically locked onto the thread subunit by formations of H-bonds with two potential stations. This macrocycle comprises two pyridine groups, which would be easily coordinated with zinc porphyrin. The Zn(II) coordination of porphyrin moiety on the thread subunit, immediately followed by the coordination with pyridine groups on the macrocycle, leads to an intermolecular axle-macrocycle-type nanostructure. Moreover, the self-assembly way shows great difference from the two states of the rotaxane monomer: The coordination-driven self-organization of the trans-state E2 leads to a network structure, whereas the cis-state Z2 gives birth to an irregular assembly.