Ligand substitution and redox properties of 4-picolylaminepentacyanoferrate(II)

Summary The stability constant for Fe^II(CN)₅(4-picam)]^3– (4-picam=4-picolylamine), K₂, was calculated from the measured dissociation and formation constants. The reduction potential obtained by cyclic voltammetry allowed the calculation of K₃. Comparison of K₂ and K₃ for this and other substituted pentacyanoferrate(II) complexes supports the fact that bonding properties of azines coordinated to {Fe(CN)₅}^n– change with the iron oxidation state. The variation on the rate of release of 4-picam with pH and added electrolyte concentration was interpreted on the basis of solvent effects.Predoctoral fellow of CONICET, República Argentina.Member of the Carrera del Investigador Científico, CONICET, República Argentina.