Dysprosium(III) chloride (DyCl
3), 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 hexa
hydrate
In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...
, DyCl
3·6H
2O. Simple rapid heating of the hydrate causes partial
hydrolysis[F. T. Edelmann, P. Poremba, in: ''Synthetic Methods of Organometallic and Inorganic Chemistry'', (W. A. Herrmann, ed.), Vol. 6, Georg Thieme Verlag, Stuttgart, 1997.] to an oxychloride, DyOCl.
Preparation and reactions
DyCl
3 is often prepared by the "
ammonium chloride route", starting from either Dy
2O
3 or the hydrated chloride DyCl
3·6H
2O.
These methods produce (NH
4)
2 yCl5
:10 NH
4Cl + Dy
2O
3 → 2 (NH
4)
2 yCl5 + 6 NH
3 + 3 H
2O
:DyCl
3·6H
2O + ''2'' NH
4Cl → (NH
4)
2 yCl5+ 6 H
2O
The pentachloride
decomposes thermally according to the following equation:
:(NH
4)
2 yCl5 → 2 NH
4Cl + DyCl
3
The thermolysis reaction proceeds via the intermediacy of (NH
4)
y2Cl7
Treating
Dy2O3 with aqueous
HCl HCL may refer to:
Science and medicine
* Hairy cell leukemia, an uncommon and slowly progressing B cell leukemia
* Harvard Cyclotron Laboratory, from 1961 to 2002, a proton accelerator used for research and development
* Hollow-cathode lamp, a spe ...
produces the hydrated chloride DyCl
3·6H
2O, which cannot be rendered anhydrous by heating. Instead one obtains an
oxychloride
In chemistry, molecular oxohalides (oxyhalides) are a group of chemical compounds in which both oxygen and halogen atoms are attached to another chemical element A in a single molecule. They have the general formula , where X = fluorine (F), chlor ...
:
:DyCl
3 + H
2O → DyOCl + 2 HCl
Dysprosium(III) chloride is a moderately strong
Lewis acid
A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any sp ...
, 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:
:DyCl
3 + 3 NaF → DyF
3 + 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 DyCl
3 in
eutectic LiCl-
KCl
Potassium chloride (KCl, or potassium salt) is a metal halide Salt (chemistry), salt composed of potassium and chlorine. It is odorless and has a white or colorless vitreous lustre, vitreous crystal appearance. The solid dissolves readily in wa ...
is
electrolysed
In chemistry and manufacturing, electrolysis is a technique that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from n ...
. The reduction occurs via Dy
2+, at a
tungsten cathode.
[Y. Castrillejo, M. R. Bermejo, A. I. Barrado, R. Pardo, E. Barrado, A. M. Martinez, ''Electrochimica Acta'', 50, 2047-2057 (2005).]
Precautions
Dysprosium compounds are believed to be of low to moderate
toxicity, although their toxicity has not been investigated in detail.
References
{{DEFAULTSORT:Dysprosium(Iii) Chloride
Dysprosium compounds
Chlorides
Lanthanide halides