Ferrioxalate

Ferrioxalate
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/3C2H2O4.Fe/c3*3-1(4)2(5)6;/h3*(H,3,4)(H,5,6);/q;;;+3/p-6
    Key: FYJLUEWYCIBBGT-UHFFFAOYSA-H
  • C(=O)(C(=O)[O-])[O-].C(=O)(C(=O)[O-])[O-].C(=O)(C(=O)[O-])[O-].[Fe+3]
Properties
C6FeO123−
Molar mass 319.901 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Ferrioxalate or trisoxalatoferrate(III) is a trivalent anion with formula [Fe(C2O4)3]3−. It is a transition metal complex consisting of an iron atom in the +3 oxidation state and three bidentate oxalate ions C2O2−4 anions acting as ligands.

The ferrioxalate anion gives a lime green color to salts, and in solution it is fluorescent. The anion is sensitive to light and higher-energy electromagnetic radiation, which causes the decomposition of one oxalate to carbon dioxide (CO2) and reduction of the iron(III) atom to iron(II). This property is exploited for actinometry.

The most common and most-studied salt is potassium ferrioxalate, but the sodium, ammonium, and lithium salts have also received some attention.