Protactinium(V) fluoride

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Protactinium(V) fluoride
Beta-UF5.png
Identifiers
3D model (JSmol)
PubChem CID
  • InChI=1S/5FH.Pa/h5*1H;/q;;;;;+5/p-5
    Key: LULSFBDYSXVRIJ-UHFFFAOYSA-I
  • F[Pa](F)(F)(F)F
Properties
F5Pa
Molar mass 326.02790 g·mol−1
Appearancewhite solid [1]
Soluble in water and hydrofluoric acid [1]
Related compounds
Other anions
protactinium(V) chloride
protactinium(V) bromide
protactinium(V) iodide
Other cations
uranium(V) fluoride
Related compounds
protactinium(IV) fluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Protactinium(V) fluoride is a fluoride of protactinium with the chemical formula PaF5.

Contents

Preparation

Protactinium(V) fluoride can be obtained by reacting protactinium(V) oxide with bromine trifluoride or bromine pentafluoride at 600 °C: [1]

It can also be obtained by reacting protactinium(V) chloride or protactinium(IV) fluoride with fluorine gas at 700 °C: [1]

The hydrate form of protactinium(V) fluoride can be formed by the reaction of protactinium(V) oxide and hydrofluoric acid in an aqueous solution: [1]

It can also be decomposed from fluorine-containing protactinium complexes. [2]

Properties

Protactinium(V) fluoride is a white, volatile, extremely hygroscopic solid that is partially soluble in water and soluble in hydrofluoric acid. It has a tetragonal crystal structure of the β-uranium pentafluoride type with the space group I42d (space group no. 122) with the lattice parameters a = 1153 pm, c = 510 pm. Quartz and Pyrex are attacked by the compound at higher temperatures. As a dihydrate, it is a colourless, hygroscopic, crystalline solid that is waxy in nature. It is soluble in water and hydrofluoric acid. [1] It reacts with phosphorus trifluoride to form protactinium(IV) fluoride. [3] The dihydrate cannot be converted into the anhydrous form in air, hydrogen fluoride or fluorine at low temperatures. Instead, diprotactinium(V) oxide octafluoride (Pa2OF8) is formed. At higher temperatures around 325 °C, a mixture of the diprotactinium(V) oxide octafluoride and protactinium(V) fluoride is formed. [2]

Related Research Articles

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Bromine is a chemical element; it has symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig and Antoine Jérôme Balard, its name was derived from the Ancient Greek βρῶμος (bromos) meaning "stench", referring to its sharp and pungent smell.

<span class="mw-page-title-main">Protactinium</span> Chemical element, symbol Pa and atomic number 91

Protactinium is a chemical element; it has symbol Pa and atomic number 91. It is a dense, radioactive, silvery-gray actinide metal which readily reacts with oxygen, water vapor, and inorganic acids. It forms various chemical compounds, in which protactinium is usually present in the oxidation state +5, but it can also assume +4 and even +3 or +2 states. Concentrations of protactinium in the Earth's crust are typically a few parts per trillion, but may reach up to a few parts per million in some uraninite ore deposits. Because of its scarcity, high radioactivity, and high toxicity, there are currently no uses for protactinium outside scientific research, and for this purpose, protactinium is mostly extracted from spent nuclear fuel.

In chemistry, an interhalogen compound is a molecule which contains two or more different halogen atoms and no atoms of elements from any other group.

<span class="mw-page-title-main">Bromine trifluoride</span> Chemical compound

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 agent and an ionizing inorganic solvent. It is used to produce uranium hexafluoride (UF6) in the processing and reprocessing of nuclear fuel.

<span class="mw-page-title-main">Bromine pentafluoride</span> Chemical compound

Bromine pentafluoride, BrF5, is an interhalogen compound and a fluoride of bromine. It is a strong fluorinating agent.

<span class="mw-page-title-main">Selenium tetrafluoride</span> Chemical compound

Selenium tetrafluoride (SeF4) is an inorganic compound. It is a colourless liquid that reacts readily with water. It can be used as a fluorinating reagent in organic syntheses (fluorination of alcohols, carboxylic acids or carbonyl compounds) and has advantages over sulfur tetrafluoride in that milder conditions can be employed and it is a liquid rather than a gas.

Bromine compounds are compounds containing the element bromine (Br). These compounds usually form the -1, +1, +3 and +5 oxidation states. Bromine is intermediate in reactivity between chlorine and iodine, and is one of the most reactive elements. Bond energies to bromine tend to be lower than those to chlorine but higher than those to iodine, and bromine is a weaker oxidising agent than chlorine but a stronger one than iodine. This can be seen from the standard electrode potentials of the X2/X couples (F, +2.866 V; Cl, +1.395 V; Br, +1.087 V; I, +0.615 V; At, approximately +0.3 V). Bromination often leads to higher oxidation states than iodination but lower or equal oxidation states to chlorination. Bromine tends to react with compounds including M–M, M–H, or M–C bonds to form M–Br bonds.

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<span class="mw-page-title-main">Barium bromide</span> Chemical compound

Barium bromide is the chemical compound with the formula BaBr2. It is ionic and hygroscopic in nature.

<span class="mw-page-title-main">Tetrafluoroammonium</span> Chemical compound

The tetrafluoroammonium cation is a positively charged polyatomic ion with chemical formula NF+
4
. It is equivalent to the ammonium ion where the hydrogen atoms surrounding the central nitrogen atom have been replaced by fluorine. Tetrafluoroammonium ion is isoelectronic with tetrafluoromethane CF
4
, trifluoramine oxide ONF
3
and the tetrafluoroborate BF
4
anion.

<span class="mw-page-title-main">Bismuth pentafluoride</span> Chemical compound

Bismuth pentafluoride is an inorganic compound with the formula BiF5. It is a white solid that is highly reactive. The compound is of interest to researchers but not of particular value.

<span class="mw-page-title-main">Bromine monofluoride</span> Chemical compound

Bromine monofluoride is a quite unstable interhalogen compound with the chemical formula BrF. It can be produced through the reaction of bromine trifluoride (or bromine pentafluoride) and bromine. Due to its lability, the compound can be detected but not isolated:

<span class="mw-page-title-main">Neptunium(VI) fluoride</span> Chemical compound

Neptunium(VI) fluoride (NpF6) is the highest fluoride of neptunium, it is also one of seventeen known binary hexafluorides. It is an orange volatile crystalline solid. It is relatively hard to handle, being very corrosive, volatile and radioactive. Neptunium hexafluoride is stable in dry air but reacts vigorously with water.

Fluorine forms a great variety of chemical compounds, within which it always adopts an oxidation state of −1. With other atoms, fluorine forms either polar covalent bonds or ionic bonds. Most frequently, covalent bonds involving fluorine atoms are single bonds, although at least two examples of a higher order bond exist. Fluoride may act as a bridging ligand between two metals in some complex molecules. Molecules containing fluorine may also exhibit hydrogen bonding. Fluorine's chemistry includes inorganic compounds formed with hydrogen, metals, nonmetals, and even noble gases; as well as a diverse set of organic compounds. For many elements the highest known oxidation state can be achieved in a fluoride. For some elements this is achieved exclusively in a fluoride, for others exclusively in an oxide; and for still others the highest oxidation states of oxides and fluorides are always equal.

<span class="mw-page-title-main">Thorium compounds</span> Chemical compounds

Many compounds of thorium are known: this is because thorium and uranium are the most stable and accessible actinides and are the only actinides that can be studied safely and legally in bulk in a normal laboratory. As such, they have the best-known chemistry of the actinides, along with that of plutonium, as the self-heating and radiation from them is not enough to cause radiolysis of chemical bonds as it is for the other actinides. While the later actinides from americium onwards are predominantly trivalent and behave more similarly to the corresponding lanthanides, as one would expect from periodic trends, the early actinides up to plutonium have relativistically destabilised and hence delocalised 5f and 6d electrons that participate in chemistry in a similar way to the early transition metals of group 3 through 8: thus, all their valence electrons can participate in chemical reactions, although this is not common for neptunium and plutonium.

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

Curium(III) fluoride or curium trifluoride is the chemical compound composed of curium and fluorine with the formula CmF3. It is a white, nearly insoluble salt that has the same crystal structure as LaF3. It precipitates as a hydrate when fluoride ions are added to a weakly acidic Cm(III) solution; alternatively it can be synthesized by reacting hydrofluoric acid with Cm(OH)3. The anhydrous form is then obtained by desiccation or by treatment with hydrogen fluoride gas.

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

Protactinium(IV) chloride is an inorganic compound. It is an actinide halide, a salt composed of protactinium and chlorine. It is radioactive, and has the chemical formula of PaCl4. It is a chartreuse-coloured (yellowish-green) crystal of the tetragonal crystal system.

Protactinium compounds are compounds containing the element protactinium. These compounds usually have protactinium in the +5 oxidation state, although these compounds can also exist in the +2, +3 and +4 oxidation states.

Bromyl fluoride is an inorganic compound of bromine, fluorine, and oxygen with the chemical formula BrO2F.

References

  1. 1 2 3 4 5 6 Brauer, Georg (1975). Handbuch der Präparativen Anorganischen Chemie. F. Enke. p. 1170. ISBN   3432023286.
  2. 1 2 G. Meyer; Lester R. Morss (1991). Synthesis of Lanthanide and Actinide Compounds (in German). Springer. p. 77. ISBN   9780792310181.
  3. Lester R. Morss; Norman M. Edelstein; J. Fuger, eds. (2010). The Chemistry of the Actinide and Transactinide Elements (in German). Vol. 1. Springer. p. 198. ISBN   978-94-0070211-0.