Properties

Neodymium(III) chloride (NdCl₃), also known as neodymium trichloride, is a compound of neodymium and chlorine. It is a mauve-coloured solid with a melting point of 758 °C and a boiling point of point 1690 °C ^[1]. Being hygroscopic it rapidly absorbs water on exposure to moist air to form a violet-coloured hexahydrate, NdCl₃.7 H₂O. This hydrate, like many neodymium salts, has the interesting property that it loses its colour under fluorescent light (see picture). It is soluble in water to the extent of 0.967 kg/L at 13 °C ^[2], and (when anhydrous) it is soluble (0.445 kg/L) in ethanol but insoluble in chloroform and ether^[2]. It has a density of 4.02 g cm^-3 and a molecular weight of 247.24. It is nine-coordinate (trigonal prismatic)^[3], and it crystallises with the UCl₃ structure^[1].

CAS Registry No:[10024-93-8] (anhydrous); [13477-89-9] (hexahydrate).

Density: 4.134 g cm^-3(anhydrous); 2.282 g cm^-3 (hexahydrate).

Molecular weight of 250.60(anhydrous) or 358.69(hexahydrate).

Preparation of anhydrous NdCl₃

Simple rapid heating of the hydrate alone may cause small amounts of hydrolysis ^[1], although the method given for drying cerium(III) chloride heptahydrate would be expected to work also for NdCl₃. Anhydrous NdCl₃ can also be made by dehydration of the hydrate either by slowly heating to 400 °C with 4-6 equivalents of ammonium chloride under high vacuum^[1],[4], or by heating with an excess of thionyl chloride for four hours^[1],[5]. The anhydrous halide may alternatively be prepared from neodymium metal and hydrogen chloride ^[6]. It is usually purified by high temperature sublimation under high vacuum. ^[1]

Uses

There are no major uses for neodymium(III) chloride, though it can be used as a starting point for the preparation of other neodymium salts.

Suppliers

Alfa: http://www.alfa.com/alf/index.htm

GFS: http://www.gfschemicals.com/productcatalog/Rare_Earth_Compounds_KO.asp

Aldrich: http://www.sigmaaldrich.com

Strem: http://www.strem.com/code/index.ghc

In the US, several of these suppliers also distribute through Fisher: https://www1.fishersci.com/index.jsp or VWR: http://www.vwr.com/index.htm

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. CRC Handbook of Chemistry and Physics (58th edition), CRC Press, West Palm Beach, Florida, 1977.
3. N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, Pergamon Press, 1984.
4. M. D. Taylor, P. C. Carter, J. Inorg. Nucl. Chem. 24, 387 (1962); J. Kutscher, A. Schneider, Inorg. Nucl. Chem. Lett. 7, 815 (1971).
5. J. H. Freeman, M. L. Smith, J. Inorg. Nucl. Chem. 7, 224 (1958).
6. L. F. Druding, J. D. Corbett, J. Am. Chem. Soc. 83, 2462 (1961); J. D. Corbett, Rev. Chim. Minerale 10, 239 (1973).