Lanthanum(III) chloride

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Lanthanum(III) chloride
UCl3 without caption.png
Cerium bromide (space filling) 2.png
Names
Other names
Lanthanum trichloride
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.030.202
UNII
Properties
LaCl3
Molar mass 245.264 g/mol (anhydrous)
353.36 g/mol (hexahydrate)
371.37 g/mol (heptahydrate)
Appearance white odorless powder
hygroscopic
Density 3.84 g/cm3[1]
Melting point 858 °C (1,576 °F; 1,131 K) (anhydrous)[1]
Boiling point 1,000 °C (1,830 °F; 1,270 K) (anhydrous)
957 g/L (25 °C)[1]
Solubility soluble in ethanol (heptahydrate)
Structure[2]
hexagonal (UCl3 type), hP8
P63/m, No. 176
a = 0.74779 nm, b = 0.74779 nm, c = 0.43745 nm
2
Tricapped trigonal prismatic,(nine-coordinate)
Related compounds
Other anions
Lanthanum oxide
Other cations
Cerium(III) chloride
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

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 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:[3]

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]

One application of lanthanum chloride is the removal of phosphate from solutions via precipitation, e.g. in swimming pools to prevent algae growth and other wastewater treatments.[4][5] 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.[6]

In organic synthesis, lanthanum trichloride functions as a mild Lewis acid for converting aldehydes to acetals.[7]

The compound has been identified as a catalyst for the high pressure oxidative chlorination of methane to chloromethane with hydrochloric acid and oxygen.[8]

References[edit]

  1. ^ a b c Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). CRC Press. p. 4.69. ISBN 978-1439855119. 
  2. ^ Morosin, B (1968). "Crystal Structures of Anhydrous Rare‐Earth Chlorides". The Journal of Chemical Physics. 49 (7): 3007–3012. doi:10.1063/1.1670543. 
  3. ^ Brauer, G., ed. (1963). Handbook of Preparative Inorganic Chemistry (2nd ed.). New York: Academic Press. 
  4. ^ Ghassemi, Masood; Recht, Howard Leonard (1971). Phosphate Precipitation with Ferrous Iron. 
  5. ^ "Water Treatment Chemicals". American Elements. Retrieved 2018-08-03. 
  6. ^ Martin, T; Allier, C; Bernard, F (2007). "Lanthanum Chloride Scintillator for X-ray Detection". AIP Conference Proceedings. 879. pp. 1156–1159. doi:10.1063/1.2436269. 
  7. ^ "Lanthanum trichloride: An efficient Lewis acid catalyst for chemo and regioselective enamination of β-dicarbonyl compounds". Arkivoc. 2007 (13): 204. 2007. doi:10.3998/ark.5550190.0008.d23. 
  8. ^ 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.