novel molecular switches based on viologen ligand and its transition metal complexes

In this work, the viologen derivative was prepared by reacted of bis (3-chloroacetylacetone) ethylenediimine (an-cl) with mono-methylviologen (c1v+). the switching motion between dicationic viologen compound c1v2+an-cl.2pf6^- and diamagnetic intermolecular π-dimer (c1v+an-cl. pf6^-)2 was triggered through the reduction by 1 electron/viologen unit. this molecular switch was followed by uv-visible absorption spectrometry. the viologen compound c1v2+an-cl.2pf6- was titrated with zn2+, cu2+, co2+, and fe2+ ions to afford metal complexes in the solution of m2+-c1v2+an-cl.2pf6-. moreover, four molecular switches were attained from those metal complexes (m2+-c1v+an-cl. pf6^-)2 by the chemical reduction stimuli including the characterization of complexes of m2+-c1v12+an-cl.2pf6^- were performed by uv-visible absorption spectroscopy. it was noticed that ratio of metal to the ligand in the complexes of zn2+, cu2+, co2+, and fe2+ was 1:1. switching properties of the novel viologen derivatives with intermolecular dimer were studied by the reduction with activated zinc powder and followed by the absorption spectroscopy. after the 1e- reduction viologen unit in c1v12+an-cl.2pf6^- and m^2+-c1v1^2+an-cl.2pf6^-, intermolecular dimerized viologen radicals occurred.