Dysprosium(III) chloride

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Dysprosium(III) chloride
Dysprosium(III) chloride hexahydrate
Identifiers
CAS number 10025-74-8 YesY
PubChem 66207
ChemSpider 59592 YesY
Jmol-3D images Image 1
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
Dysprosium(III) oxide
Other cations Terbium(III) chloride
Dysprosium(II) chloride
Holmium(III) chloride
Related compounds Dysprosium(II) chloride
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox 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.

Preparation and reactions[edit]

DyCl3 is often prepared by the "ammonium chloride route," starting from either Dy2O3 or hydrated chloride or oxychloride.[2][3] or DyCl3·6H2O.[4] These methods produce (NH4)2[DyCl5]:

10 NH4Cl + Dy2O3 → 2 (NH4)2[DyCl5] + 6 NH3 + 3 H2O
DyCl3·6H2O + 2 NH4Cl → (NH4)2[DyCl5] + 6 H2O

The pentachloride decomposes thermally according to the following equation:

(NH4)2[DyCl5] → 2 NH4Cl + DyCl3

The thermolysis reaction proceeds via the intermediacy of (NH4)[Dy2Cl7].

Treating Dy2O3 with aqueous HCl produces hydrated chloride (DyCl3·6H2O). This salt cannot be rendered anhydrous by heating. Instead one obtains an oxychloride.


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 other dysprosium(III) compounds, for example dysprosium(III) fluoride:

DyCl3 + 3 NaF → DyF3 + 3 NaCl

Uses[edit]

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.[5]

Precautions[edit]

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

References[edit]

  1. ^ 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. ^ Meyer, G. (1989). "The Ammonium Chloride Route to Anhydrous Rare Earth Chlorides-The Example of YCl3". Inorganic Syntheses 25: 146–150. doi:10.1002/9780470132562.ch35. ISBN 978-0-470-13256-2. 
  3. ^ Edelmann, F. T.; Poremba, P. (1997). Herrmann, W. A. (ed.), ed. Synthetic Methods of Organometallic and Inorganic Chemistry VI. Stuttgart: Georg Thieme Verlag. ISBN 3-13-103021-6. 
  4. ^ Taylor, M.D.; Carter, C.P. "Preparation of anhydrous lanthanide halides, especially iodides". Journal of Inorganic and Nuclear Chemistry 24 (4): 387–391. doi:10.1016/0022-1902(62)80034-7. 
  5. ^ Y. Castrillejo, M. R. Bermejo, A. I. Barrado, R. Pardo, E. Barrado, A. M. Martinez, Electrochimica Acta, 50, 2047-2057 (2005).