Dysprosium(II) chloride explained

Dysprosium(II) chloride (DyCl₂), also known as dysprosium dichloride, is an ionic chemical compound of dysprosium and chlorine. This salt is a reduced compound, as the normal oxidation state of dysprosium in dysprosium compounds is +3.

Dysprosium dichloride is glossy black in appearance. The salt is damaged by oxidation on exposure to air. It is an electrical insulator.^[1]

The structure is the same as for strontium bromide, ytterbium dichloride, and terbium dichloride. There are two forms. The low temperature form is below 652 °C. It is orthorhombic with unit cell dimensions a=6.69, b=6.76, and c=7.06 Å.^[2]

Preparation

Dysprosium dichloride can be prepared by heating molten dysprosium trichloride with dysprosium metal, and rapidly quenching. Molybdenum, niobium or tantalum crucibles are required to avoid alloy formation with the dysprosium.^[3]

Reactions

Dysprosium dichloride is capable of reducing titanium dichloride to titanium metal in a potassium chloride, sodium chloride flux.^[4]

Ti²⁺ + 2Dy²⁺ → Ti (solid) + 2Dy³⁺

Related

A ternary dysprosium(II) chloride compound is known with lithium: LiDy₂Cl₅. This is produced by heating lithium metal and dysprosium trichloride together at 700 °C. This compound is also black. The crystal system of LiDy₂Cl₅ is monoclinic with space group C2/c 4 formulae per unit cell which has dimensions ; a = 16.45.6(; b = 6.692; and c = 7.267; with β = 95.79°.^[5]

Notes and References

1. Book: Macintyre . Jane E. . Dictionary of Inorganic Compounds . 1992-07-23 . CRC Press . 978-0-412-30120-9 . 2867 . en.
2. Corbett . John D. . McCollum . Bill C. . Rare Earth Metal-Metal Halide Systems. IX. The Dysprosium-Dysprosium(III) Chloride System and the Preparation of Dysprosium(II) Chloride . Inorganic Chemistry . May 1966 . 5 . 5 . 938–940 . 10.1021/ic50039a050.
3. Book: Advances in Inorganic Chemistry and Radiochemistry . 1977-09-01 . Academic Press . 978-0-08-057869-9 . 8 . en.
4. Yasuda . Kouji . Saegusa . Kunio . Okabe . Toru H. . Aluminum Subhalide as a Reductant for Metallothermic Reduction . High Temperature Materials and Processes . January 2011 . 30 . 4–5 . 411 . 10.1515/htmp.2011.063. 2011HTMP...30..411Y . free .
5. Meyer . Gerd . Reduced ternary rare earth halides: State of the art . Journal of the Less Common Metals . September 1983 . 93 . 2 . 371–380 . 10.1016/0022-5088(83)90190-X.