Praseodymium(III) chloride

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Praseodymium(III) chloride
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IUPAC name
Praseodymium(III) chloride
Other names
Praseodymium chloride; praseodymium trichloride
3D model (JSmol)
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PubChem CID
  • InChI=1S/3ClH.Pr/h3*1H;/q;;;+3/p-3
  • Cl[Pr](Cl)Cl
Molar mass 247.24 g/mol (anhydrous)
373.77 g/mol (heptahydrate)
Appearanceblue-green solid (anhydrous)
light green solid (heptahydrate)
Density 4.02 g/cm3 (anhydrous)
2.250 g/cm3 (heptahydrate)
Melting point 786 °C (1,447 °F; 1,059 K)
Boiling point 1,710 °C (3,110 °F; 1,980 K)
104.0 g/100 ml (13 °C)
+44.5·10−6 cm3/mol
hexagonal (UCl3 type), hP8
P63/m, No. 176
Tricapped trigonal prismatic
Occupational safety and health (OHS/OSH):
Main hazards
Related compounds
Other anions
Praseodymium(III) oxide, Praseodymium(III) fluoride
Praseodymium bromide
praseodymium iodide
Other cations
Cerium(III) chloride
Neodymium(III) chloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Praseodymium(III) chloride is the inorganic compound with the formula Pr Cl 3. Like other lanthanide trichlorides, it exists both in the anhydrous and hydrated forms. It is a blue-green solid that rapidly absorbs water on exposure to moist air to form a light green heptahydrate.



Praseodymium(III) chloride is prepared by treating praseodymium metal with hydrogen chloride: [1] [2]

2 Pr + 6 HCl → 2 PrCl3 + 3 H2

It is usually purified by vacuum sublimation. [3]

Hydrated salts of praseodymium(III) chloride can be prepared by treatment of either praseodymium metal or praseodymium(III) carbonate with hydrochloric acid:

Pr2(CO3)3 + 6 HCl + 15 H2O → 2 [Pr(H2O)9]Cl3 + 3 CO2

PrCl3∙7H2O is a hygroscopic substance, that will not crystallise from the mother liquor unless it is left to dry in a dessiccator. Anhydrous PrCl3 can be made by thermal dehydration of the hydrate at 400 °C in the presence of ammonium chloride, the so-called ammonium chloride route. [3] [4] Alternatively the hydrate can be dehydrated using thionyl chloride. [3] [5]


Praseodymium(III) chloride is Lewis acidic, classified as "hard" according to the HSAB concept. Rapid heating of the hydrate may cause small amounts of hydrolysis. [3] PrCl3 forms a stable Lewis acid-base complex K2PrCl5 by reaction with potassium chloride; this compound shows interesting optical and magnetic properties. [1]

Aqueous solutions of praseodymium(III) chloride can be used to prepare insoluble praseodymium(III) compounds. For example, praseodymium(III) phosphate and praseodymium(III) fluoride can be prepared by reaction with potassium phosphate and sodium fluoride, respectively:

PrCl3 + K3PO4 → PrPO4 + 3 KCl
PrCl3 + 3 NaF → PrF3 + 3 NaCl
2PrCl3 + 3 Na2CO3----> Pr2CO3 + 6NaCl

When heated with alkali metal chlorides, it forms a series of ternary (compounds containing three different elements) materials with the formulae MPr2Cl7, M3PrCl6, M2PrCl5, and M3Pr2Cl9 where M = K, Rb, Cs. [6]

Related Research Articles

<span class="mw-page-title-main">Iron(III) chloride</span> Inorganic compound

Iron(III) chloride is the inorganic compound with the formula FeCl3. Also called ferric chloride, it is a common compound of iron in the +3 oxidation state. The anhydrous compound is a crystalline solid with a melting point of 307.6 °C. The color depends on the viewing angle: by reflected light the crystals appear dark green, but by transmitted light they appear purple-red.

<span class="mw-page-title-main">Cerium(III) chloride</span> Chemical compound

Cerium(III) chloride (CeCl3), also known as cerous chloride or cerium trichloride, is a compound of cerium and chlorine. It is a white hygroscopic salt; it rapidly absorbs water on exposure to moist air to form a hydrate, which appears to be of variable composition, though the heptahydrate CeCl3·7H2O is known. It is highly soluble in water, and (when anhydrous) it is soluble in ethanol and acetone.

Neodymium(III) chloride or neodymium trichloride is a chemical compound of neodymium and chlorine with the formula NdCl3. This anhydrous compound is a mauve-colored solid that rapidly absorbs water on exposure to air to form a purple-colored hexahydrate, NdCl3·6H2O. Neodymium(III) chloride is produced from minerals monazite and bastnäsite using a complex multistage extraction process. The chloride has several important applications as an intermediate chemical for production of neodymium metal and neodymium-based lasers and optical fibers. Other applications include a catalyst in organic synthesis and in decomposition of waste water contamination, corrosion protection of aluminium and its alloys, and fluorescent labeling of organic molecules (DNA).

<span class="mw-page-title-main">Samarium(III) chloride</span> Chemical compound

Samarium(III) chloride, also known as samarium trichloride, is an inorganic compound of samarium and chloride. It is a pale yellow salt that rapidly absorbs water to form a hexahydrate, SmCl3.6H2O. The compound has few practical applications but is used in laboratories for research on new compounds of samarium.

<span class="mw-page-title-main">Cobalt(II) chloride</span> Chemical compound

Cobalt(II) chloride is an inorganic compound of cobalt and chlorine, with the formula CoCl
. The compound forms several hydrates CoCl
, for n = 1, 2, 6, and 9. Claims of the formation of tri- and tetrahydrates have not been confirmed. The anhydrous form is a blue crystalline solid; the dihydrate is purple and the hexahydrate is pink. Commercial samples are usually the hexahydrate, which is one of the most commonly used cobalt compounds in the lab.

<span class="mw-page-title-main">Chromium(III) chloride</span> Chemical compound

Chromium(III) chloride (also called chromic chloride) describes any of several chemical compounds with the formula CrCl3 · xH2O, where x can be 0, 5, and 6. The anhydrous compound with the formula CrCl3 is a violet solid. The most common form of the trichloride is the dark green hexahydrate, CrCl3 · 6 H2O. Chromium chlorides find use as catalysts and as precursors to dyes for wool.

<span class="mw-page-title-main">Rhodium(III) chloride</span> Chemical compound

Rhodium(III) chloride refers to inorganic compounds with the formula RhCl3(H2O)n, where n varies from 0 to 3. These are diamagnetic solids featuring octahedral Rh(III) centres. Depending on the value of n, the material is either a dense brown solid or a soluble reddish salt. The soluble trihydrated (n = 3) salt is widely used to prepare compounds used in homogeneous catalysis, notably for the industrial production of acetic acid and hydroformylation.

<span class="mw-page-title-main">Iridium(III) chloride</span> Chemical compound

Iridium(III) chloride is the inorganic compound with the formula IrCl3. The anhydrous compound is relatively rare, but the related hydrate is useful for preparing other iridium compounds. The anhydrous salt is a dark green crystalline solid. More commonly encountered is the trihydrate IrCl3(H2O)3.

<span class="mw-page-title-main">Uranium(III) chloride</span> Chemical compound

Uranium(III) chloride, UCl3, is a water soluble salt of uranium. UCl3 is used mostly to reprocess spent nuclear fuel. Uranium(III) chloride is synthesized in various ways from uranium(IV) chloride; however, UCl3 is less stable than UCl4.

<span class="mw-page-title-main">Yttrium(III) chloride</span> Chemical compound

Yttrium(III) chloride is an inorganic compound of yttrium and chloride. It exists in two forms, the hydrate (YCl3(H2O)6) and an anhydrous form (YCl3). Both are colourless solids that are highly soluble in water and deliquescent.

<span class="mw-page-title-main">Ytterbium(III) chloride</span> Chemical compound

Ytterbium(III) chloride (YbCl3) is an inorganic chemical compound. It reacts with NiCl2 to form a very effective catalyst for the reductive dehalogenation of aryl halides. It is poisonous if injected, and mildly toxic by ingestion. It is an experimental teratogen, known to irritate the skin and eyes. When heated to decomposition it emits toxic fumes of Cl.

<span class="mw-page-title-main">Metal bis(trimethylsilyl)amides</span>

Metal bis(trimethylsilyl)amides are coordination complexes composed of a cationic metal with anionic bis(trimethylsilyl)amide ligands and are part of a broader category of metal amides.

<span class="mw-page-title-main">Metal halides</span>

Metal halides are compounds between metals and halogens. Some, such as sodium chloride are ionic, while others are covalently bonded. A few metal halides are discrete molecules, such as uranium hexafluoride, but most adopt polymeric structures, such as palladium chloride.

Lanthanide trichlorides are a family of inorganic compound with the formula LnCl3, where Ln stands for a lanthanide metal. The trichlorides are standard reagents in applied and academic chemistry of the lanthanides. They exist as anhydrous solids and as hydrates.

<span class="mw-page-title-main">Neodymium acetate</span> Compound of neodymium

Neodymium acetate is an inorganic salt composed of a neodymium atom trication and three acetate groups as anions where neodymium exhibits the +3 oxidation state. It has a chemical formula of Nd(CH3COO)3 although it can be informally referred to as NdAc because Ac is an informal symbol for acetate. It commonly occurs as a light purple powder.

<span class="mw-page-title-main">Neodymium compounds</span> Chemical compounds with at least one neodymium atom

Neodymium compounds are compounds formed by the lanthanide metal neodymium (Nd). In these compounds, neodymium generally exhibits the +3 oxidation state, such as NdCl3, Nd2(SO4)3 and Nd(CH3COO)3. Compounds with neodymium in the +2 oxidation state are also known, such as NdCl2 and NdI2. Some neodymium compounds have colors that vary based upon the type of lighting.

<span class="mw-page-title-main">Berkelium(III) chloride</span> Chemical compound

Berkelium(III) chloride also known as berkelium trichloride, is a chemical compound with the formula BkCl3. It is a water-soluble green solid with a melting point of 603 °C. This compound forms the hexahydrate, BkCl3·6H2O.

<span class="mw-page-title-main">Praseodymium(III) iodide</span> Chemical compound

Praseodymium(III) iodide is an inorganic salt, consisting of the rare-earth metal praseodymium with hydrogen iodide with the chemical formula PrI3, with green crystals. It is soluble in water.

<span class="mw-page-title-main">Terbium compounds</span> Chemical compounds with at least one terbium atom

Terbium compounds are compounds formed by the lanthanide metal terbium (Tb). In these compounds, terbium generally exhibits the +3 oxidation state, such as TbCl3, Tb(NO3)3 and Tb(CH3COO)3. Compounds with terbium in the +4 oxidation state are also known, such as TbO2 and BaTbF6. Terbium can also form in the 0, +1 and +2 oxidation states.

<span class="mw-page-title-main">Lanthanum(III) iodide</span> Chemical compound

Lanthanum(III) iodide is an inorganic compound containing lanthanum and iodine with the chemical formula LaI


  1. 1 2 J. Cybinska, J. Sokolnicki, J. Legendziewicz, G. Meyer, Journal of Alloys and Compounds, 341, 115–123 (2002).
  2. L. F. Druding, J. D. Corbett, "Lower Oxidation States of the Lanthanides. Neodymium(II) Chloride and Iodide", J. Am. Chem. Soc.83, 2462 (1961); J. D. Corbett, Rev. Chim. Minerale10, 239 (1973),
  3. 1 2 3 4 F. T. Edelmann, P. Poremba, in: Synthetic Methods of Organometallic and Inorganic Chemistry, (W. A. Herrmann, ed.), Vol. 6, Georg Thieme Verlag, Stuttgart, 1997.
  4. M. D. Taylor, P. C. Carter, "Preparation of anhydrous lanthanide halides, especially iodides", 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, "The preparation of anhydrous inorganic chlorides by dehydration with thionyl chlorid", J. Inorg. Nucl. Chem., 7, 224 (1958).
  6. Gerd Meyer, "Ternary Chlorides and Bromides of the Rare-Earth Elements", Inorganic Syntheses, 1990, Volume 30, pp. 72–81. doi : 10.1002/9780470132616.ch15

Further reading

  1. CRC Handbook of Chemistry and Physics (58th edition), CRC Press, West Palm Beach, Florida, 1977.
  2. N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, Pergamon Press, 1984.
  3. S. Sugiyama, T. Miyamoto, H. Hayashi, M. Tanaka, J. B. Moffatt, "Effects of chlorine additives in the gas- and solid-phases on the oxidative dehydrogenation of ethane over praseodymium oxide", Journal of Molecular Catalysis A, 118, 129-136 (1997).
  4. Druding L. F.; Corbett J. D.; Ramsey B. N. (1963). "Rare Earth Metal-Metal Halide Systems. VI. Praseodymium Chloride". Inorganic Chemistry . 2 (4): 869–871. doi:10.1021/ic50008a055.