Electrode-deposited films of polyrotaxanes: electrochemically induced gliding motion

Using the three-dimensional template effect of copper(I) or copper(lr), a macrocycle incorporating two different chelating units was threaded by a coordinating molecular fragment whose two ends bear pyrrole nuclei; after electropolymerization, an electroactive film was obtained that clearly showed pirouetting of the ring induced by reducing the five-coordinate copper(II) complex to copper(I). The motion is driven by the difference in the stereoelectronic preferences of copper(I) and copper(II). The present system allows motions of the monovalent complex only.