| Names | |
|---|---|
| IUPAC name
Erbium(III) chloride | |
| Other names
Erbium trichloride | |
| Identifiers | |
| |
3D model (JSmol) |
|
| ChemSpider | |
| ECHA InfoCard | 100.030.337 |
| EC Number |
|
PubChem CID |
|
| UNII | |
CompTox Dashboard (EPA) |
|
| |
| |
| Properties | |
| 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) |
| soluble in water (anhydrous) slightly soluble in ethanol (hexahydrate) | |
| Structure | |
| monoclinic | |
| C2/m, No. 12 | |
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).
| |
Erbium(III) chloride is a violet solid with the formula ErCl3. It is used in the preparation of erbium metal.

Anhydrous erbium(III) chloride can be produced by the ammonium chloride route. In the first step, erbium(III) oxide is heated with ammonium chloride to produce the ammonium salt of the pentachloride:
In the second step, the ammonium chloride salt is converted to the trichloride by heating in a vacuum at 350-400 °C:
Erbium(III) chloride forms crystals of the AlCl3 type, with monoclinic crystals and the point group C2/m.
Erbium(III) chloride hexahydrate also forms monoclinic crystals with the point group of P2/n (P2/c) - C42h. In this compound, erbium is octa-coordinated to form [Er(H2O)6Cl2]+ ions with the isolated Cl− completing the structure.
Erbium(III) chloride solutions show a negative nonlinear absorption effect.[clarification needed]
The use of erbium(III) chloride as a catalyst has been demonstrated in the acylation of alcohols and phenols and in an amine functionalisation of furfural. It is a catalyst for Friedel–Crafts-type reactions, and can be used in place of cerium(III) chloride for Luche reductions.