Tetraazamacrocyclic copper(II) complexes linked by the system of conjugated double bonds with one or two benzo-15-crown-5 ether moieties (4Cu and 5Cu) as well as model compounds were synthesized and characterized. The CV of these complexes in acetonitrile (ACN) solution exhibited reversible Cu-II/I redox process. Complexation of Na+ and Mg2+ cations with 5Cu in the gas phase was confirmed by electrospray mass spectrometry. In solution complexation of Li+ and Na+ with 5Cu was weak. Complexation of Cl- anion to coordinated copper in 5Cu resulted in an appreciable shift in the Cu-II/I redox potential after addition of studied cations. The addition of increasing amounts of Mg2+ cation to the solution of 5Cu resulted in a significant shift of the Cu-II/I reduction process accompanied by further reduction to Cu-O followed by replacement of copper by Mg2+ cation. Barium(II) cation interacted only with reduced (Cu+) form of 5Cu. (C) 2004 Elsevier Ltd. All rights reserved.