Voltammetric investigation of iron(III) complexes with siderophore chrysobactin in aqueous solution

Voltammetric investigations of iron(III)–chrysobactin complexes in aqueous solution at static mercury electrode, were performed. With c_Fe = (0.5–30) × 10^?7 mol dm^?3 and c_Cb = (0.5–100) × 10^?7 mol dm^?3 in pH range 6.7–10, reduction peaks with E_p ?0.64 to ?0.74 V (1) and E_p ?0.50 to ?0.62 V (2) vs. Ag/AgCl, were registered. These reduction processes were time dependent as well as solution composition (c_Fe, c_Cb and pH). Complexes are adsorbed at the mercury drop surface. Presumed stoichiometry of the detected complexes was Fe^IIICb₃ (1) and Fe^IIICb₂(OH)_x (2). Their formation/dissociation processes were described. These investigations are of biological importance as well, since provide an insight into possible reduction mechanism in the bacterial cells that use chrysobactin to acquire the iron.