Potassium ferrooxalate
Names
IUPAC name
Potassium iron(II) oxalate
Other names
potassium ferrooxalate
potassium bisoxalatoferrate(II)
Identifiers
3D model (JSmol)
  • InChI=1S/2C2H2O4.Fe.2K/c2*3-1(4)2(5)6;;;/h2*(H,3,4)(H,5,6);;;/q;;+2;2*+1/p-4
    Key: LDRXJDFKHOUYMS-UHFFFAOYSA-J
  • [K+].[K+].O=C(-C(=O)O1)O[Fe-2]12OC(-C(=O)O2)=O
Properties
K
2[Fe(C
2O
4)
2] (anhydrous)
K
2[Fe(C
2O
4)
2]·2H
2O (dihydrate)
Appearance orange-yellow solid (anhydrous), golden-yellow crystals (dihydrate) [1]
Melting point decomposes at 470 °C [1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Potassium ferrooxalate, also known as potassium bisoxalatoferrate(II), is a salt with the formula K2Fe(C2O4)2(H2O)x. The anion is a transition metal oxalate complex, consisting of an atom of iron in the +2 oxidation state bound to oxalate (C
2O2−
4) ligands and water.[2]

Anhydrous K2Fe(C2O4)2 has been prepared by hydrothermal methods from ferrous chloride. It is a coordination polymer with trigonal prismatic Fe(C2O4)3 centers. Half of the oxalate ligands are bridging.[3]

Dihydrate

The material K2Fe(C2O4)2(H2O)2 has been claimed[1] but not verified.Potassium ferrooxalate is believed to be formed when the related compound potassium ferrioxalate K
3[Fe(C
2O
4)
3] is decomposed by light in solution (a common method of actinometry) or heated above 296 °C.[1] The anhydrous salt is orange-yellow and dissolves in water to give a red solution. Crystals of the dihydrate K
2[Fe(C
2O
4)
2]·2H
2O are golden yellow in color.[1]


See also

A number of other iron oxalates are known

References

  1. ^ a b c d e J. Ladriere (1992): "Mössbauer study on the thermal decomposition of potassium tris (oxalato) ferrate(III) trihydrate and bis (oxalato) ferrate(II) dihydrate". Hyperfine Interactions, volume 70, issue 1, pages 1095–1098. doi:10.1007/BF02397520
  2. ^ Amanchar, Sara; Schweitzer, Thierry; Mazet, Thomas; Malaman, Bernard; Diop, Leopold V. B.; Francois, Michel (2023). "Structure of the new iron(II) oxalate potassium salt K2Fe[(C2O4)2(H2O)2]·0.18H2O". Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials. 79 (4): 263–270. doi:10.1107/S2052520623004602. PMID 37347140. S2CID 259223071.
  3. ^ Hursthouse, Michael B.; Light, Mark E.; Price, Daniel J. (2004). "One-Dimensional Magnetism in Anhydrous Iron and Cobalt Ternary Oxalates with Rare Trigonal-Prismatic Metal Coordination Environment". Angewandte Chemie International Edition. 43 (4): 472–475. doi:10.1002/anie.200352406. PMID 14735538.
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