Dysprosium(III) chloride
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Dysprosium(III)_chloride".

Dysprosium(III) chloride
IUPAC name	Dysprosium(III) chloride Dysprosium trichloride
Identifiers
CAS number	[10025-74-8]
Properties
Molecular formula	DyCl3
Molar mass	268.86 g/mol (anhydrous)
Appearance	white solid
Density	3.67 g/cm³, solid
Melting point	647 °C (anhydrous)
Boiling point	1530 °C
Solubility in water	Soluble
Structure
Crystal structure	AlCl3 structure
Coordination geometry	Octahedral
Hazards
EU classification	not listed
Flash point	non flammable
Related compounds
Other anions	Dysprosium(III) fluoride Dysprosium(III) bromide Dysprosium(III) iodide
Other cations	Terbium(III) chloride Dysprosium(II) chloride Holmium(III) chloride
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Dysprosium(III) chloride (DyCl₃), also known as dysprosium trichloride, is a compound of dysprosium and chlorine. It is a white to yellow solid which rapidly absorbs water on exposure to moist air to form a hexahydrate, DyCl₃.6H₂O. Simple rapid heating of the hydrate causes partial hydrolysis^[1] to an oxychloride, DyOCl.

Chemical properties

Dysprosium(III) chloride is a moderately strong Lewis acid, which ranks as "hard" according to the HSAB concept. Aqueous solutions of dysprosium chloride can be used to prepare insoluble dysprosium(III) compounds, for example dysprosium(III) fluoride:

DyCl₃(aq) + 3 NaF(aq) → DyF₃(s) + 3 NaCl(aq)

Preparation

Dysprosium(III) chloride can be prepared as a yellow aqueous solution by reaction of either dysprosium metal or dysprosium(III) carbonate and hydrochloric acid.

2 Dy(s) + 6 HCl(aq) → 2 DyCl₃(aq) + 3 H₂(g)

Dy₂(CO₃)₃(s) + 6 HCl(aq) → 2 DyCl₃(aq) + 3 CO₂(g) + 3 H₂O(l)

Anhydrous DyCl₃ can be made by dehydration of the hydrate either by slowly heating to 400 °C with 4-6 equivalents of ammonium chloride under high vacuum.^[1][2] The anhydrous halide may alternatively be prepared from dysprosium metal and hydrogen chloride^[3]. It is usually purified by high temperature sublimation under high vacuum.^[1]

Uses

Dysprosium(III) chloride can be used as a starting point for the preparation of other dysprosium salts. Dysprosium metal is produced when a molten mixture of DyCl₃ in eutectic LiCl-KCl is electrolysed. The reduction occurs via Dy²⁺, at a tungsten cathode.^[4]

Precautions

Dysprosium compounds are believed to be of low to moderate toxicity, although their toxicity has not been investigated in detail.

References

1. ^ ^{a b c} F. T. Edelmann, P. Poremba, in: Synthetic Methods of Organometallic and Inorganic Chemistry, (W. A. Herrmann, ed.), Vol. 6, Georg Thieme Verlag, Stuttgart, 1997.
2. ^ M. D. Taylor, P. C. Carter, J. Inorg. Nucl. Chem. 24, 387 (1962); J. Kutscher, A. Schneider, Inorg. Nucl. Chem. Lett. 7, 815 (1971).
3. ^ L. F. Druding, J. D. Corbett, J. Am. Chem. Soc. 83, 2462 (1961); J. D. Corbett, Rev. Chim. Minerale 10, 239 (1973).
4. ^ Y. Castrillejo, M. R. Bermejo, A. I. Barrado, R. Pardo, E. Barrado, A. M. Martinez, Electrochimica Acta, 50, 2047-2057 (2005).