Английская Википедия:Dysprosium(III) chloride

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Шаблон:Chembox

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 the hydrated chloride DyCl3·6H2O.[2][3][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 the hydrated chloride DyCl3·6H2O, which cannot be rendered anhydrous by heating. Instead one obtains an oxychloride:[3]

DyCl3 + H2O → DyOCl + 2 HCl

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

  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. Шаблон:Cite book
  3. 3,0 3,1 Шаблон:Cite journal
  4. Шаблон:Cite book
  5. Y. Castrillejo, M. R. Bermejo, A. I. Barrado, R. Pardo, E. Barrado, A. M. Martinez, Electrochimica Acta, 50, 2047-2057 (2005).

Шаблон:Dysprosium compounds Шаблон:Chlorides Шаблон:Lanthanide halides