A green, water-soluble solid, it is produced by the reaction of iron metal with dilute perchloric acid followed by evaporation of the solution:[3] Although the ferrous cation is a reductant and the perchlorate anion is a strong oxidant, in the absence of atmospheric oxygen, dissolved ferrous perchlorate is stable in aqueous solution because the electron transfer between both species Fe2+ and ClO−4 is hindered by severe kinetic limitations.

Being a weak Lewis base, the perchlorate anion is a poor ligand for the aqueous Fe2+ and does not contribute to the electron transfer by favoring the formation of an inner sphere complex giving rise to a possible reorganisation of the activated complex.

The resulting high activation energy prohibits a thermodynamically spontaneous redox reaction (∆Gr < 0).

[4] The hexahydrate consists of discrete hexa-aquo-iron(II) divalent cations and perchlorate anions.

[2] It has minor phase transitions at 245 and 336 K.[5] In organic chemistry, iron(II) perchlorate can be used as a source of ferrous ions for the Fenton oxidation.