Iron oxychloride

Iron oxychloride is the inorganic compound with the formula FeOCl. This purple solid adopts a layered structure, akin to that of cadmium chloride.[1] The material slowly hydrolyses in moist air. The solid intercalates electron donors such as tetrathiafulvalene and even pyridine to give mixed valence charge-transfer salts. Intercalation is accompanied by a marked increase in electrical conductivity and a color change to black.[2]

Iron oxychloride
IUPAC name
Iron oxychloride
3D model (JSmol)
ECHA InfoCard 100.054.740
EC Number
  • 260-233-0
Molar mass 107.29 g·mol−1
Appearance Vivid, dark violet, opaque crystals
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

FeOCl is prepared by heating iron(III) oxide with ferric chloride at 370 °C over the course of several days:[2]

Fe2O3 + FeCl3 → 3 FeOCl


  1. ^ Lind, M. D. (1970-08-15). "Refinement of the crystal structure of iron oxychloride". Acta Crystallographica Section B. 26 (8): 1058–1062. doi:10.1107/s0567740870003618.
  2. ^ a b Kikkawa, S.; Kanamaru, F.; Koizumi, M.; Rich, Suzanne M.; Jacobson, Allan (1984-01-01). Holt, Smith L. Jr. (ed.). Layered Intercalation Compounds. John Wiley & Sons. pp. 86–89. doi:10.1002/9780470132531.ch17. ISBN 9780470132531.