Ion-Exchange Processes M(II) → Fe(III) and Fe(III) → M(II) in Metal Hexacyanoferrate(II) Gelatin-Immobilized Matrices (M = Mn, Co, Ni, Cu, Zn, Cd)

Abstract

Ion-exchange reactions M2+ → Fe3+ and Fe3+ → M2+ (M = Mn, Co, Ni, Cu, Zn, Cd) were studied in metal(II) hexacyanoferrate(II) gelatin-immobilized matrices M2[Fe(CN)6] in contact with aqueous FeCl3 solutions and Fe4[Fe(CN)6]3 in contact with aqueous MCl2 solutions. It was shown that in both cases, M2+ was replaced by Fe3+ and Fe3+ was replaced by M2+ to some extent, but no complete replacement was observed in the M2[Fe(CN)6]–FeCl3 or Fe4[Fe(CN)6]3–MCl2 systems under study. No electrophilic substitution Fe3+ → Mn2+ was found to occur in any noticeable degree during the contact of Fe4[Fe(CN)6]3 with aqueous MnCl2 solutions even when this contact occurred for 1 h and longer.