Lanthanum(III) chloride explained

Lanthanum chloride is the inorganic compound with the formula LaCl₃. It is a common salt of lanthanum which is mainly used in research. It is a white solid that is highly soluble in water and alcohols.

Preparation

Anhydrous lanthanum(III) chloride can be produced by the ammonium chloride route.^{[1] [2] [3]} In the first step, lanthanum oxide is heated with ammonium chloride to produce the ammonium salt of the pentachloride:

La₂O₃ + 10NH₄Cl → 2(NH₄)₂LaCl₅ + 6H₂O + 6NH₃In the second step, the ammonium chloride salt is converted to the trichlorides by heating in a vacuum at 350-400 °C:

(NH₄)₂LaCl₅ → LaCl₃ + 2HCl + 2NH₃

Uses

Lanthanum chloride is also used in biochemical research to block the activity of divalent cation channels, mainly calcium channels. Doped with cerium, it is used as a scintillator material.^[4]

In organic synthesis, lanthanum trichloride functions as a mild Lewis acid for converting aldehydes to acetals.^[5]

The compound has been identified as a catalyst for the high pressure oxidative chlorination of methane to chloromethane with hydrochloric acid and oxygen.^[6]

Also used in the field of geology as a very dilute solution, which when combined with the proper acids can help identify small >1% Strontium content in powdered rock samples.

Notes and References

1. Book: Handbook of Preparative Inorganic Chemistry. 2nd. Brauer, G. . Academic Press. 1963. New York.
2. Book: Meyer , G. . The Ammonium Chloride Route to Anhydrous Rare Earth Chlorides-The Example of YCl₃. The Ammonium Chloride Route to Anhydrous Rare Earth Chlorides—The Example of Ycl ₃. Inorganic Syntheses. 25. 1989. 146–150. 10.1002/9780470132562.ch35. 978-0-470-13256-2.
3. Book: Edelmann, F. T. . Synthetic Methods of Organometallic and Inorganic Chemistry . VI . Poremba, P. . Herrmann, W. A. . 1997 . Georg Thieme Verlag . Stuttgart . 978-3-13-103021-4 .
4. Book: 10.1063/1.2436269. Lanthanum Chloride Scintillator for X-ray Detection. AIP Conference Proceedings. 879. 1156–1159. 2007. Martin. T. Allier. C. Bernard. F.
5. 10.3998/ark.5550190.0008.d23. Lanthanum trichloride: An efficient Lewis acid catalyst for chemo and regioselective enamination of β-dicarbonyl compounds. Arkivoc. 2007. 13. 204–209. 2007. free. Lenin. R.. Raju. R. Madhusudhan.
6. Podkolzin SG, Stangland EE, Jones ME, Peringer E, Lercher JA . Methyl chloride production from methane over lanthanum-based catalysts . J. Am. Chem. Soc. . 129 . 9 . 2569–76 . 2007 . 17295483 . 10.1021/ja066913w. free .