Lanthanum(III) chloride

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Lanthanum(III) chloride
UCl3 without caption.png Cerium bromide (space filling) 2.png
Identifiers
CAS number 10099-58-8 YesY
20211-76-1 (heptahydrate)
PubChem 64735
ChemSpider 58275 YesY
Jmol-3D images Image 1
Properties
Molecular formula LaCl3
Molar mass 245.26 g/mol (anhydrous)
353.36 g/mol (hexahydrate)
371.37 g/mol (heptahydrate)
Appearance white odorless powder
hygroscopic
Density 3.84 g/cm3
Melting point 858 °C (anhydrous)[1]
Boiling point 1000 °C (anhydrous)
Solubility in water very soluble
Solubility soluble in ethanol (heptahydrate)
Structure
Crystal structure hexagonal (UCl3 type), hP8
Space group P63/m, No. 176
Coordination
geometry
Tricapped trigonal prismatic,(nine-coordinate)
Hazards
EU Index Not listed
Related compounds
Other anions Lanthanum oxide
Other cations Cerium(III) chloride
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

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

Structure[edit]

The La3+ centre is 9-coordinate in the trichloride. The structure is similar to that for uranium trichloride.

Preparation and reactions[edit]

It forms upon union of the elements, but a more commonly used method involves heating a mixture of lanthanum(III) oxide and ammonium chloride at 200-250 °C:[2]

La2O3 + 6 NH4Cl → 2 LaCl3 + 6 NH3 + 2 H2O

From the trichloride, one can produce the other trihalides by exchange. Reduction with potassium gives metallic lanthanum.

Uses[edit]

Lanthanum chloride does not enjoy many applications. A possible application involves the precipitation phosphate from solutions, e.g. in swimming pools to prevent algae growth. It has also shown use as a filter aid and an effective flocculent. 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.

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

The compound has been identified as a catalyst for the high pressure oxidative chlorination of methane to chloromethane with hydrochloric acid and oxygen.[3]

This compound is also used in Gamma Detectors, is one of the smallest sized (massed) meters of the inorganic compounds used for Gamma Ray Detectors.

References[edit]

  1. ^ Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3. 
  2. ^ Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY.
  3. ^ Podkolzin SG, Stangland EE, Jones ME, Peringer E, Lercher JA (2007). "Methyl chloride production from methane over lanthanum-based catalysts". J. Am. Chem. Soc. 129 (9): 2569–76. doi:10.1021/ja066913w. PMID 17295483.