Dysprosium(III) chloride
| Dysprosium(III) chloride | |
|---|---|
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| IUPAC name Dysprosium(III) chloride | |
| Identifiers | |
| CAS number | 10025-74-8  |
| PubChem | 66207 |
| ChemSpider | 59592 |
| Jmol-3D images | {{#if:Cl[Dy](Cl)Cl|Image 1 |
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| 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 |
| Related compounds | Dysprosium(II) chloride |
(verify) (what is: / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |
| 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
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
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
Dysprosium compounds are believed to be of low to moderate toxicity, although their toxicity has not been investigated in detail.
References
- ↑ F. T. Edelmann, P. Poremba, in: Synthetic Methods of Organometallic and Inorganic Chemistry, (W. A. Herrmann, ed.), Vol. 6, Georg Thieme Verlag, Stuttgart, 1997.
- ↑ 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.
- ↑ 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.
- ↑ 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.
- ↑ Y. Castrillejo, M. R. Bermejo, A. I. Barrado, R. Pardo, E. Barrado, A. M. Martinez, Electrochimica Acta, 50, 2047-2057 (2005).
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