Nitrosymmetallochelates—I. Mechanism of FeNO—EDTA complex formation and its oxidation

A nitrosyliron(II) complex with EDTA was produced by reaction of the Fe(II)—EDTA complex and nitrous acid in citric acid—phosphate buffer solution. The experimental results pointed out that nitrous acid is reduced to nitrous oxide by Fe(II)—EDTA complex followed by the formation reaction of nitrosyliron(II) EDTA complex. The composition of this complex was determined to be Fe(II) (NO)₂EDTA by both electrochemical and spectroscopic methods.A mechanism of the oxidation of Fe(II) (NO)₂EDTA was proposed in which nitrous oxide breaks away from the iron ion. The photoeffect on this reaction is discussed.