Erbium(III) chloride

Erbium(III) chloride
IUPAC name Erbium(III) chloride
Other names Erbium trichloride
Identifiers
CAS number	10138-41-7 Y
ChemSpider	59656 Y
Jmol-3D images	Image 1
SMILES Cl[Er](Cl)Cl
InChI InChI=1S/3ClH.Er/h3*1H;/q;;;+3/p-3 Y Key: HDGGAKOVUDZYES-UHFFFAOYSA-K Y InChI=1/3ClH.Er/h3*1H;/q;;;+3/p-3 Key: HDGGAKOVUDZYES-DFZHHIFOAE
Properties
Molecular formula	ErCl3 (anhydrous) ErCl3·6H2O (hexahydrate)
Molar mass	273.62 g/mol (anhydrous) 381.71 g/mol (hexahydrate)
Appearance	violet hygroscopic monoclinic crystals (anhydrous) pink hygroscopic crystals (hexahydrate)
Density	4.1 g/cm3 (anhydrous)
Melting point	776 °C (anhydrous) decomposes (hexahydrate)
Boiling point	1500 °C
Solubility in water	soluble in water (anhydrous) slightly soluble in ethanol (hexahydrate)[1]
Y chloride (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Erbium(III) chloride, the erbium(III) salt of hydrochloric acid, is a violet solid used for the preparation of erbium metal.

Properties

Erbium(III) chloride hydrate photographed under a fluorescent lamp

It is also found as a pink crystalline hexahydrate, CAS number [10025-75-9]. It has the interesting property that the pink colour is much more intense under the light from a fluorescent lamp, as may be seen from the picture.

Anhydrous erbium(III) chloride is formed from the hexahydrate by heating under a strongly chlorinating atmosphere, such as chlorine or hydrogen chloride; otherwise erbium oxide chloride, ErOCl, is formed. An alternative preparation is to react the readily available Er₂O₃ with excess NH₄Cl to make the intermediate salt (NH₄)₃ErCl₆ plus both ammonia and water. This salt is stable with respect to hydrolysis and can be thermally decomposed under vacuum to yield anhydrous erbium(III) chloride with loss of ammonia and gaseous HCl.

It reacts with alkalis to form erbium(III) hydroxide:

ErCl₃ + 3 XOH → Er(OH)₃ + 3 XCl

Structural data

Erbium chloride forms crystals of the AlCl₃ type, with monoclinic crystals and the point group C2/m.^[2]

Erbium(III) chloride hexahydrate also forms monoclinic crystals with the point group of P2/n (P2/c) - C⁴_2h. The erbium is octa-coordinated to form [Er(H₂O)₆Cl₂]⁺ ions with the isolated Cl⁻ completing the structure.^[3]

Optical properties

Erbium(III) chloride solutions show a negative nonlinear absorption effect.^[4]

Catalytic properties

Erbium(III) chloride is a powerful catalyst for the acylation of alcohols and phenols, and can be easily recycled and reused without significant loss of activity. ^[5]

References

1. ^ Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, FL: CRC Press. pp. 4–57. ISBN 0-8493-0594-2 
2. ^ Tempelton DH, Carter GF (1954). "The Crystal Structure of Yttrium Trichloride and Similar Compounds". J Phys Chem 58 (11): 940–943. doi:10.1021/j150521a002. 
3. ^ Graebner EJ, Conrad GH Duliere SF (1966). Crystallographic data for solvated rare earth chlorides. 21. pp. 1021. 
4. ^ Maeda Y, Akidzuki Y, Yamada T (1998). "All-optical liquid device derived from negative nonlinear absorption effect in an erbium chloride solution". Applied Physics Letters 73 (17): 2411–2413. doi:10.1063/1.122450. 
5. ^ CSIRO PUBLISHING - Australian Journal of Chemistry