Cyano lambda3-iodanes react with iron(II) and iron(III) complexes as cyano-transfer one-electron oxidants. This approach enables the straightforward synthesis of iron(III) and iron(IV) cyanide complexes, which have been thoroughly characterized by spectroscopic methods, including X-ray diffraction, EPR, Mössbauer and NMR spectroscopies and computational methods. We disclose a new reactivity mode for electrophilic cyano lambda3-iodanes as group