Iron(III) perchlorate
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3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.033.538 |
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CompTox Dashboard (EPA) |
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| Properties | |
| Fe(ClO4)3 | |
| Molar mass | 354.19 g/mol (anhydrous) 516.34 g/mol (nonahydrate) |
| Appearance | Canary yellow solid (anhydrous)[1] Pale violet solid (nonahydrate)[2] |
| Density | 2.03 g/cm3 (nonahydrate)[3] |
| Melting point | 110 °C (230 °F; 383 K)[2] (decomposition, nonahydrate) |
| nonahydrate 74.32 g/100 mL (0 °C) 79.86 g/100 mL (25 °C)[4] | |
| Structure[3] | |
| Trigonal | |
| R3c | |
a = 16.19 Å, c = 11.24 Å | |
Lattice volume (V) |
2553 Å3 |
| octahedral (around Fe) | |
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| Related compounds | |
Other anions |
Iron(III) nitrate |
Other cations |
Manganese(II) perchlorate Cobalt(II) perchlorate |
Related compounds |
Iron(II) perchlorate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Iron(III) perchlorate, also known as ferric perchlorate, is an inorganic chemical compound with the formula Fe(ClO4)3·nH2O, where n can range from 0 to 9. The most common form is the nonahydrate, Fe(ClO4)3·9H2O, which is a hygroscopic pale violet crystalline solid, but samples are often partially hydrolyzed and/or contaminated with iron(III) chloride, giving them a yellow color.[5]
History
[edit]Iron(III) perchlorate was first observed by Georges-Simon Serullas in 1831 as an oxidation product of iron(II) perchlorate, who was attempting to produce various metal perchlorates after Friedrich von Stadion discovered the perchlorate ion. However, it was not properly characterized until 1935 by Folke Lindstrand.[6][7][2]
Preparation
[edit]The nonahydrate is produced by refluxing a mixture of iron(III) oxide-hydroxide and aqueous 70% perchloric acid:[2]
- FeO(OH) + 3 HClO4 → Fe(ClO4)3 + 2 H2O
It can also be prepared by the reaction of iron(III) chloride and aqueous perchloric acid, followed by repeated recrystallization in perchloric acid.[5][8]
In comparison, the synthesis of the anhydrous form is much more difficult. It is produced by the reaction of iron(III) chloride and dichlorine hexoxide at 20 °C:[1][9]
- 2 FeCl3 + 7 Cl2O6 → ClO2Fe2(ClO4)7 + 6 ClO2 + 3 Cl2
The resulting ClO2Fe2(ClO4)7 is heated under a vacuum at 60 °C to yield the canary yellow anhydrous iron(III) perchlorate.[1]
Hydrates other than the nonahydrate, such as the hexahydrate, from the dehydration of the nonahydrate in the presence of sulfuric acid, and the dihydrate, from the reaction of anhydrous perchloric acid and iron(III) chloride, have been reported.[9][10]
Structure
[edit]The nonahydrate, structurally formulated [Fe(H2O)6](ClO4)3·3H2O, has a trigonal crystal structure and consists of discrete octahederal [Fe(H2O)6]3+ centers as well as perchlorate and three molecules of water of crystallization.[3][8]
The anhydrous form, which has been probed by IR spectroscopy, consists of bidentate perchlorate ligands.[1]
Reactions and applications
[edit]Iron(III) perchlorate dissolves in water to form [Fe(H2O)6]3+ and ClO4– ions. The [Fe(H2O)6]3+ partially hydrolyses:[11][12]
- [Fe(H2O)6]3+ ⇌ [Fe(H2O)5OH]2+ + H+
Dilute solutions of iron(III) perchlorate slowly precipitate iron(III) hydroxide particles, whereas concentrated solutions do not, because the higher acidity prevents hydroxide formation. Hydrolysis can also be suppressed by adding perchloric acid. The above behavior parallels that of iron(III) nitrate solutions.[11][12]
The nonahydrate decomposes at around 110 °C to an unknown basic perchlorate. The anhydrous form, when heated, similarly decomposes to an unknown basic perchlorate.[2][1]
Iron(III) perchlorate has very limited applications in organic synthesis. The anhydrous and dihydrate have been studied as a cationic polymerization initiator for alkenes. The nonahydrate has been studied for use as a catalyst in various organic reactions, including multicomponent condensation reactions.[10][13][14][15]
References
[edit]- 1 2 3 4 5 Moncef Chaabouni; Jean-Louis Pascal; André Claude Pavia; Jacqueline Potier; Antoine Potier (1978). "Les perchlorates anhydres de fer" [Anhydrous iron perchlorates]. Comptes Rendus de l'Académie des Sciences, Série C (in French). 287: 419–422. Retrieved 24 May 2026.
- 1 2 3 4 5 Lindstrand, Folke (1936). "Über Eisenperchlorate. I". Zeitschrift für anorganische und allgemeine Chemie. 230 (1–2): 187–208. Bibcode:1936ZAACh.230..187L. doi:10.1002/zaac.19362300119. ISSN 0863-1786.
- 1 2 3 Hennings, Erik; Schmidt, Horst; Voigt, Wolfgang (2014). "Crystal structure of iron(III) perchlorate nonahydrate". Acta Crystallographica Section E. 70 (12): 477–479. Bibcode:2014AcCrE..70..477H. doi:10.1107/S1600536814024295. ISSN 1600-5368. PMC 4257414. PMID 25552970.
- ↑ Dale L. Perry (2016). Handbook of Inorganic Compounds. CRC Press. p. 171. ISBN 9781439814628. Retrieved 24 May 2026.
- 1 2 Weinland, R.; Loebich, O. (1926). "Über die Ferrisalze substituierter Essigsäuren sowie der Malonsäure und ihre Konstitution". Zeitschrift für anorganische und allgemeine Chemie. 151 (1): 271–288. Bibcode:1926ZAACh.151..271W. doi:10.1002/zaac.19261510127. ISSN 0863-1786.
- ↑ Schilt, Alfred A. (1979). Perchloric acid and perchlorates. The G. Frederick Smith Chemical Company.
- ↑ Georges-Simon Serullas (1831). "Emploi de l'Acide oxichlorique (perchlorique) comme réactif propre à distinguer et à séparer la soude de la potasse libre ou combinée à d'autres acids. — Oxichlorates" [Use of Oxychloric (Perchloric) Acid as a Reagent for Distinguishing and Separating Soda from Potash, Whether Free or Combined with Other Acids — Oxychlorates]. Annales de chimie et de physique (in French). 46: 297–308. Retrieved 24 May 2026.
- 1 2 Skogareva, L. S.; Shilov, G. V.; Karelin, A. I. (2012). "Crystal structure and Raman spectra of [Fe(H2O)6]3+(ClO−4)3·3H2O". Journal of Structural Chemistry. 53 (5): 907–914. doi:10.1134/S0022476612050113. ISSN 0022-4766. Retrieved 2026-05-24.
- 1 2 Pascal, Jean-Louis; Favier, Frédéric (1998). "Inorganic Perchlorato Complexes". Coordination Chemistry Reviews. 178–180: 865–902. doi:10.1016/S0010-8545(98)00102-7.
- 1 2 Thirupathi, Ponnaboina; Kim, Sung Soo (2010). "Fe(ClO4)3·×H2O-Catalyzed direct C–C bond forming reactions between secondary benzylic alcohols with different types of nucleophiles". Tetrahedron. 66 (16): 2995–3003. doi:10.1016/j.tet.2010.02.063.
- 1 2 Magini, M. (1978). "An X-ray investigation on the structure of iron(III) perchlorate solutions". Journal of Inorganic and Nuclear Chemistry. 40 (1): 43–48. doi:10.1016/0022-1902(78)80304-2.
- 1 2 Hsu, Pa Ho (1973). "Appearance and Stability of Hydrolyzed Fe(ClO 4 ) 3 Solutions". Clays and Clay Minerals. 21 (5): 267–277. Bibcode:1973CCM....21..267H. doi:10.1346/CCMN.1973.0210502. ISSN 0009-8604. Retrieved 2026-05-24.
- ↑ Arabpourian, K.; Behbahani, F. K. (2019). "Synthesis of Pyrrole Derivatives Promoted by Fe(ClO4)3/SiO2 as an Environmentally Friendly Catalyst". Russian Journal of Organic Chemistry. 55 (5): 682–685. doi:10.1134/S1070428019050166. ISSN 1070-4280.
- ↑ Heravi, Majid M.; Behbahani, Farahnaz K.; Daraie, Mansoureh; Oskooie, Hossein A. (2009). "Fe(ClO4)3·6H2O: a mild and efficient catalyst for one-pot three component synthesis of β-acetamido carbonyl compounds under solvent-free conditions". Molecular Diversity. 13 (3): 375–378. doi:10.1007/s11030-009-9118-z. ISSN 1381-1991. PMID 19241133.
- ↑ Najafi, E.; Behbahani, F. K. (2017). "Three-component synthesis of 3-(diarylmethyl)indoles using Fe(ClO4)3/SiO2 as catalyst". Russian Journal of Organic Chemistry. 53 (3): 454–458. doi:10.1134/S107042801703023X. ISSN 1070-4280.
