Praseodymium(III) fluoride is an

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

PrF₃, being the most stable

fluoride Fluoride (). According to this source, is a possible pronunciation in British English. is an Inorganic chemistry, inorganic, Monatomic ion, monatomic Ion#Anions and cations, anion of fluorine, with the chemical formula (also written ), whose ...

praseodymium Praseodymium is a chemical element; it has symbol Pr and atomic number 59. It is the third member of the lanthanide series and is considered one of the rare-earth metals. It is a soft, silvery, malleable and ductile metal, valued for its magnetic ...

Preparation

The reaction between praseodymium(III) nitrate and

sodium fluoride Sodium fluoride (NaF) is an inorganic compound with the formula . It is a colorless or white solid that is readily soluble in water. It is used in trace amounts in the fluoridation of drinking water to prevent tooth decay, and in toothpastes ...

will obtain praseodymium(III) fluoride as a green crystalline solid: : Pr(NO₃)₃ + 3 NaF → 3 NaNO₃ + PrF₃ There are also literature reports on the reaction between

chlorine trifluoride Chlorine trifluoride is an interhalogen compound with the formula . It is a colorless, poisonous, corrosive, and extremely reactive gas that condenses to a pale-greenish yellow liquid, the form in which it is most often sold (pressurized at room ...

and various oxides of praseodymium (Pr₂O₃, Pr₆O₁₁ and PrO₂), where praseodymium(III) fluoride is the only product. The reaction between

bromine trifluoride Bromine trifluoride is an interhalogen compound with the formula BrF3. At room temperature, it is a straw-coloured liquid with a pungent odor which decomposes violently on contact with water and organic compounds. It is a powerful fluorinating a ...

and praseodymium oxide left in the air for a period of time also produces praseodymium(III) fluoride, but the reaction is incomplete; the reaction between praseodymium(III) oxalate hydrate and bromine trifluoride can obtain praseodymium(III) fluoride, and carbon is also produced from this reaction. Praseodymium(III) fluoride can also be obtained by reacting praseodymium oxide and

sulfur hexafluoride Sulfur hexafluoride or sulphur hexafluoride ( British spelling) is an inorganic compound with the formula SF6. It is a colorless, odorless, non-flammable, and non-toxic gas. has an octahedral geometry, consisting of six fluorine atoms attache ...

at 584 °C.

Properties

Physical

Praseodymium(III) fluoride forms pale green crystals of trigonal system (or hexagonal system), space group P 3c1, (or P 6/mcm), cell parameters ''a'' = 0.7078 nm, ''c'' = 0.7239 nm, Z = 6, structure like cerium(III) fluoride (CeF₃).

Chemical

Praseodymium(III) fluoride is a green, odourless, hygroscopic solid that is insoluble in water.

Uses

Praseodymium(III) fluoride is used as a doping material for laser crystals.

References