Iron(III) acetate

Iron(III) acetate[1]
IUPAC name

iron(III) acetate
Other names

basic iron(III) acetate , iron(III) oxyacetate, iron(III) Acetate
Identifiers
CAS number 1834-30-6
ChemSpider 144555
Properties
Molecular formula C14H27Fe3O18
Molar mass 233 g/mol
Appearance brownish-red amorphous powder
Solubility in water insoluble
Solubility soluble in ethanol
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Ferric acetate is the coordination compound more commonly known as "basic iron acetate". With the formula [Fe3O(OAc)6(H2O)3]OAc (OAc is CH3CO2-), it is a salt, composed of the cation [Fe3(μ3-O)(OAc)6(H2O)3]+ and an acetate anion.[2] The formation of the red-brown complex has long been used as a test for ferric ions.[3]

Contents

Structure and synthesis

Basic iron acetate forms on treating aqueous solutions of iron(III) sources with acetate salts.[4]

Early work showed that it is trinuclear.[5] The Fe centres are equivalent, each being octahedral, being bound to six oxygen ligands, including a triply bridging oxide at the center of the equilateral triangle.[6] The compound was an early example of a molecular compound of iron that features an oxide ligand. Ignoring its 24 hydrogen centres, the cation has D3h symmetry.

Reactions

The terminal aqua ligands on the trimetallic framework can be substituted with other ligands, such as pyridine and dimethylformamide. Many different salts are known by exchanging the anion, e.g. [Fe3(μ3-O)(OAc)6(H2O)3]Cl. Reduction of the cation affords the neutral mixed-valence derivative that contains one ferrous and two ferric centers.[2] Mixed metal species are known such as [Fe2CoO(OAc)6(H2O)3].[7]

Related compounds

Chromium(III), ruthenium(III), vanadium(III), and rhodium(III) form analgous compounds.[8] Iron(III) acetate (lacking the oxo ligand) has been claimed as a red coloured compound from the reaction of silver acetate and iron(III) chloride.[9]

Uses

Materials prepared by heating iron, acetic acid, and air, loosely described as basic iron acetates, are used as dyes and mordants.[2]

References

  1. ^ Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, FL: CRC Press. pp. 4–63. ISBN 0849305942. 
  2. ^ a b c J. Burgess, M. V. Twigg "Iron: Inorganic & Coordination Chemistry" Encyclopedia of Inorganic Chemistry, R. Bruce King, Editor, J. Wiley, ISBN 978-0-470-86078-6
  3. ^ H. Brearley, F. Ibbotson "The Analysis of Steel-Works Materials," 1902, Longmans, Green, &Co.: London.
  4. ^ Manual of Chemistry , W. Simon , p.474 google books link
  5. ^ R. Weinland and E. Gussmann, "Über Salze einer Hexaacetato(formiato)-trichrombase. II" Berichte der Deutschen Chemischen Gesellschaft 1909, volume 42, 2997-3018). doi:10.1002/cber.19090420318.
  6. ^ Figgis, B. N.; Robertson, G. B. “Crystal-Molecular Structure and Magnetic Properties of Cr3(CH3.COO)6OCl.5H2O” Nature 1965, volume 205, pages 694-5. doi:10.1038/205694a0. This paper describes the isostructure chromium and iron compounds.
  7. ^ Blake, A. B. Yavari, A.; Hatfield, W. E.; Sethulekshmi, C. N. “Magnetic and Spectroscopic Properties of Some Heterotrinuclear Basic Acetates of Chromium(III), Iron(III), and Divalent Metal Ions” Journal of the Chemical Society, Dalton Transactions, 1985, pp. 2509-2520. doi:10.1039/DT9850002509.
  8. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
  9. ^ Ram C. Paul, Ramesh C. Narula and Sham K. Vasisht "Iron(III) acetates" Transition Metal Chemistry, 1978, Volume 3, pp.35-38. doi:10.1007/BF01393501.