VOLTAMMETRIC TITRATION OF THE COMPLEX [(FETIM)(H2O)(2)](2+) IN AN AQUEOUS-SOLUTION

The electrochemical behavior of iron complexes with TIM macrocyclic ligands [Fe-(II)>TIM(H2O)(2)](2+) (TIM = 2,3,9,10-tetramethyl-1,4,8,11-telraazacyclotetradeca-1,3,8,10-tetraene) were studied, using NaNO3 (mu = 0.1) as the supporting electrolyte on a vitreous carbon electrode, and Ag/AgCl as the reference electrode. All the solutions were deoxygenated using argon. The temperature of the cell was maintained at 25 degrees C. The protonation constants were determined by cyclic voltammetry. Spectroelectrochemical data suggest the appearance of a metallic ion in a low oxidation state in a complex of the Fe-II/Fe-I couple, observed at a low potential in cyclic voltammetric experiments.