Using the three-dimensional template effect of copper(I) or copper(lr), a m
acrocycle incorporating two different chelating units was threaded by a coo
rdinating molecular fragment whose two ends bear pyrrole nuclei; after elec
tropolymerization, an electroactive film was obtained that clearly showed p
irouetting of the ring induced by reducing the five-coordinate copper(II) c
omplex to copper(I). The motion is driven by the difference in the stereoel
ectronic preferences of copper(I) and copper(II). The present system allows
motions of the monovalent complex only.