Protactinium(IV) chloride

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Protactinium(IV) chloride
Kristallstruktur Uran(IV)-chlorid.png
IUPAC name
Protactinium(IV) chloride
3D model (JSmol)
  • InChI=1S/4ClH.Pa/h4*1H;/q;;;;+4/p-4
  • [Pa](Cl)(Cl)(Cl)Cl
Molar mass 372.848 g mol−1
Appearance chartreuse
Density 4.72 g/cm3
tetragonal [1] ,tI20
I41/amd , No. 141
Related compounds
Other anions
Protactinium(IV) fluoride
Protactinium(IV) bromide
Protactinium(IV) iodide
Other cations
Uranium(IV) chloride
Thorium(IV) chloride
Praseodymium(III) chloride
Related compounds
Protactinium(V) chloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Protactinium(IV) chloride is an inorganic compound. It is an actinide halide, composed of protactinium and chlorine. It is radioactive, and has the chemical formula of PaCl4. It is a chartreuse-coloured (yellowish-green) crystal [1] of the tetragonal crystal system.



Protactinium(IV) chloride can be prepared by the reduction of protactinium(V) chloride: [2]

It can also be obtained by the chlorination of protactinium(IV) oxide: [2]

It can also be formed during the thermal decomposition of protactinium oxychloride at 500 °C in a vacuum: [3]


Protactinium(IV) chloride is a chartreuse, hygroscopic, crystalline solid that can be sublimed at 400 °C in a vacuum. It is soluble in strong mineral acids, forming green solutions. The complex PaCl4·4CH3CN is formed with acetonitrile. It has a tetragonal crystal structure with the space group I41/amd (space group no. 141) and the lattice parameters a = 837.7 pm, c = 747.9 pm [2] of the uranium(IV) chloride type. [4]

Related Research Articles

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

Protactinium is a chemical element with the symbol Pa and atomic number 91. It is a dense, 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 organic chemistry, an acyl chloride is an organic compound with the functional group −C(=O)Cl. Their formula is usually written R−COCl, where R is a side chain. They are reactive derivatives of carboxylic acids. A specific example of an acyl chloride is acetyl chloride, CH3COCl. Acyl chlorides are the most important subset of acyl halides.

<span class="mw-page-title-main">Acyl halide</span> Oxoacid compound with an –OH group replaced by a halogen

In organic chemistry, an acyl halide is a chemical compound derived from an oxoacid by replacing a hydroxyl group with a halide group.

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">Thionyl chloride</span> Inorganic compound (SOCl2)

Thionyl chloride is an inorganic compound with the chemical formula SOCl2. It is a moderately volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a chlorinating reagent, with approximately 45,000 tonnes per year being produced during the early 1990s, but is occasionally also used as a solvent. It is toxic, reacts with water, and is also listed under the Chemical Weapons Convention as it may be used for the production of chemical weapons.

<span class="mw-page-title-main">Benzoyl chloride</span> Organochlorine compound (C7H5ClO)

Benzoyl chloride, also known as benzenecarbonyl chloride, is an organochlorine compound with the formula C7H5ClO. It is a colourless, fuming liquid with an irritating odour, and consists of a benzene ring with an acyl chloride substituent. It is mainly useful for the production of peroxides but is generally useful in other areas such as in the preparation of dyes, perfumes, pharmaceuticals, and resins.

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

Tantalum(V) chloride, also known as tantalum pentachloride, is an inorganic compound with the formula TaCl5. It takes the form of a white powder and is commonly used as a starting material in tantalum chemistry. It readily hydrolyzes to form tantalum(V) oxychloride (TaOCl3) and eventually tantalum pentoxide (Ta2O5); this requires that it be synthesised and manipulated under anhydrous conditions, using air-free techniques.

<span class="mw-page-title-main">Organoactinide chemistry</span> Study of chemical compounds containing actinide-carbon bonds

Organoactinide chemistry is the science exploring the properties, structure and reactivity of organoactinide compounds, which are organometallic compounds containing a carbon to actinide chemical bond.

<span class="mw-page-title-main">Berkelium compounds</span> Any chemical compound having at least one berkelium atom

Berkelium forms a number of chemical compounds, where it normally exists in an oxidation state of +3 or +4, and behaves similarly to its lanthanide analogue, terbium. Like all actinides, berkelium easily dissolves in various aqueous inorganic acids, liberating gaseous hydrogen and converting into the trivalent oxidation state. This trivalent state is the most stable, especially in aqueous solutions, but tetravalent berkelium compounds are also known. The existence of divalent berkelium salts is uncertain and has only been reported in mixed lanthanum chloride-strontium chloride melts. Aqueous solutions of Bk3+ ions are green in most acids. The color of the Bk4+ ions is yellow in hydrochloric acid and orange-yellow in sulfuric acid. Berkelium does not react rapidly with oxygen at room temperature, possibly due to the formation of a protective oxide surface layer; however, it reacts with molten metals, hydrogen, halogens, chalcogens and pnictogens to form various binary compounds. Berkelium can also form several organometallic compounds.

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

Niobium oxychloride is the inorganic compound with the formula NbOCl3. It is a white, crystalline, diamagnetic solid. It is often found as an impurity in samples of niobium pentachloride, a common reagent in niobium chemistry.

In chemistry, molecular oxohalides (oxyhalides) are a group of chemical compounds in which both oxygen and halogen atoms are attached to another chemical element A in a single molecule. They have the general formula AOmXn, where X = fluorine (F), chlorine (Cl), bromine (Br), and/or iodine (I). The element A may be a main group element, a transition element or an actinide. The term oxohalide, or oxyhalide, may also refer to minerals and other crystalline substances with the same overall chemical formula, but having an ionic structure.

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

Neptunium(III) chloride or neptunium trichloride is an inorganic compound with a chemical formula NpCl3. This salt is strongly radioactive.

Neptunium silicide is a binary inorganic compound of neptunium and silicon with the chemical formula NpSi
. The compound forms crystals and does not dissolve in water.

Curium compounds are compounds containing the element curium (Cm). Curium usually forms compounds in the +3 oxidation state, although compounds with curium in the +4, +5 and +6 oxidation states are also known.

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.

Protactinium(V) bromide is an inorganic compound. It is a halide of protactinium, consisting of protactinium and bromine. It is radioactive and has a chemical formula of PaBr5, which is a red crystal of the monoclinic crystal system.

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

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

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

Protactinium(IV) bromide is an inorganic compound. It is an actinide halide, composed of protactinium and bromine. It is radioactive, and has the chemical formula of PaBr4. It may be due to the brown color of bromine that causes the appearance of protactinium(IV) bromide to be brown crystals. Its crystal structure is tetragonal. Protactinium(IV) bromide is sublimed in a vacuum at 400 °C. The protactinium(IV) halide closest in structure to protactinium(IV) bromide is protactinium(IV) chloride.

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.

Americium compounds are compounds containing the element americium (Am). These compounds can form in the +2, +3 and +4, although the +3 oxidation state is the most common. The +5, +6 and +7 oxidation states have also been reported.


  1. 1 2 Brown D., Hall T.L., Moseley P.T (1973). "Structural parameters and unit cell dimensions for the tetragonal actinide tetrachlorides(Th, Pa, U, and Np) and tetrabromides (Th and Pa)". J. Chem. Soc., Dalton Trans. (6): 686–691. doi:10.1039/DT9730000686.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  2. 1 2 3 Georg Brauer (Hrsg.), unter Mitarbeit von Marianne Baudler u. a.: Handbuch der Präparativen Anorganischen Chemie. 3., umgearbeitete Auflage. Band I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6, pp. 1176.
  3. Harry Julius Emeleus, A. G. Sharpe (1970), ADVANCES IN INORGANIC CHEMISTRY AND RADIOCHEMISTRY (in German), Academic Press, p. 15, ISBN   978-0-08057861-3
  4. Lester R. Morss, Norman M. Edelstein, J. Fuger (Hrsg.): . Bände 1-6. Springer, Dordrecht 2010, ISBN 978-94-007-0211-0, S. 201 (English, in Google Books).