Erbium(III) chloride

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

Preparation

[Image:Erbium(III) chloride in fluorescent light.jpg|thumb|200px|left|Erbium(III) chloride hydrate photographed under a fluorescent lamp]
Anhydrous erbium 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:

Structural data

Erbium chloride forms crystals of the [aluminium chloride|] type, with monoclinic crystals and the point group C2/m.
Erbium chloride hexahydrate also forms monoclinic crystals with the point group of P2/n - C⁴_2h. In this compound, erbium is octa-coordinated to form ions with the isolated completing the structure.

Optical properties

Erbium chloride solutions show a negative nonlinear absorption effect.

Catalytic properties

The use of erbium 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.