Ferrioxalate

Ferrioxalate

Identifiers
CAS Number	15321-61-6
3D model (JSmol)	Interactive image
ChemSpider	146351
PubChem CID	167279
InChI 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
SMILES C(=O)(C(=O)[O-])[O-].C(=O)(C(=O)[O-])[O-].C(=O)(C(=O)[O-])[O-].[Fe+3]
Properties
Chemical formula	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). Infobox references

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.