Erbium(III) chloride

Erbium(III) chloride is a violet solid with the formula ErCl₃. It is used in the preparation of erbium metal.

Erbium(III) chloride

Erbium(III) chloride hydrate photographed in sunlight
Names
IUPAC name Erbium(III) chloride
Other names Erbium trichloride
Identifiers
CAS Number	10138-41-7 (anhydrous) N
3D model (JSmol)	Interactive image
ChemSpider	59656 Y
ECHA InfoCard	100.030.337
EC Number	233-385-0
PubChem CID	66277
UNII	867J5QOF46 N
CompTox Dashboard (EPA)	DTXSID5064966
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
SMILES Cl[Er](Cl)Cl
Properties
Chemical 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 (1,429 °F; 1,049 K) (anhydrous) decomposes (hexahydrate)
Boiling point	1,500 °C (2,730 °F; 1,770 K)
Solubility in water	soluble in water (anhydrous) slightly soluble in ethanol (hexahydrate)[1]
Structure[2]
Crystal structure	monoclinic
Space group	C2/m, No. 12
Lattice constant	a = 6.80 Å, b = 11.79 Å, c = 6.39 Å α = 90°, β = 110.7°, γ = 90°
Lattice volume (V)	479 Å3
Formula units (Z)	4
Related compounds
Other anions	Erbium(III) oxide
Other cations	Holmium(III) chloride, Thulium(III) chloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Preparation

Erbium(III) chloride hydrate photographed under a fluorescent lamp

Anhydrous erbium(III) chloride can be produced by the ammonium chloride route.^[3][4][5] In the first step, erbium(III) oxide is heated with ammonium chloride to produce the ammonium salt of the pentachloride:

Er₂O₃ + 10 [NH₄]Cl → 2 [NH₄]₂ErCl₅ + 6 H₂O + 6 NH₃

In the second step, the ammonium chloride salt is converted to the trichloride by heating in a vacuum at 350-400 °C:

[NH₄]₂ErCl₅ → ErCl₃ + 2 HCl + 2 NH₃

Structural data

Erbium(III) 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. In this compound, erbium is octa-coordinated to form [Er(H₂O)₆Cl₂]⁺ ions with the isolated Cl⁻ completing the structure.^[6]

Optical properties

Erbium(III) chloride solutions show a negative nonlinear absorption effect.^{[7][clarification needed]}

Catalytic properties

The use of erbium(III) chloride as a catalyst has been demonstrated in the acylation of alcohols and phenols^[8] and in an amine functionalisation of furfural.^[9] It is a catalyst for Friedel–Crafts-type reactions, and can be used in place of cerium(III) chloride for Luche reductions.^[10]