Electrochemical formation of bi- versus tetranuclear μ-oxo terpyridine manganese complexes in CH3CN. Influence of the terpyridine substituents

► High-valent oxo-bridged manganese multinuclear complexes are electrochemical prepared. ► They are quantitatively formed by oxidation of MnII(terpy)2 complexes in CH3CN/1M H2O. ► The nuclearity of these oxo species depends on the bulkiness of the terpy subtituents. They are fully characterized by UV-visible and EPR spectroscopy.