Linear organic–inorganic heterometallic copolymers [(Fe, Zn)(H2O)3{NH(CH2PO3H)3}]n and [(Fe, Cd)(H2O)3{NH(CH2PO3H)3}]n: The missing link in the mechanism of inhibiting local steel corrosion with phosphonates

Heteropolynuclear [Zn_0.5Fe_0.5(H₂O)₃{NH(CH₂PO₃H)₃}]_n and [Cd_0.125Fe_0.875(H₂O)₃{NH(CH₂PO₃H)₃}]_n complexes, which form during interaction between inhibitors of corrosion and Fe2+ ions and play an important role in inhibiting local steel corrosion by complexes of nitrilotrismethylenephosphonic acid, are isolated for the first time. Their composition, structure, and properties are studied by means of XSA, EDRS, IR and Raman spectroscopy.