Americium(III) chloride
| Names | |
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| IUPAC name
Americium(III) chloride
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| Systematic IUPAC name
Americium(3+) chloride | |
| Other names
Americium chloride
Americium trichloride | |
| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
PubChem CID
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| Properties | |
| AmCl3 | |
| Molar mass | 349 g·mol−1 |
| Appearance | Light red, opaque crystals |
| Density | 5.87 g cm−3[1] |
| Melting point | 715 °C (1,319 °F; 988 K)[2] |
| Boiling point | 850 °C (1,560 °F; 1,120 K)[1] |
| Structure | |
| hexagonal (UCl3 type), hP8 | |
| P63/m, No. 176 | |
| Tricapped trigonal prismatic (nine-coordinate) | |
| Related compounds | |
Other anions
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Americium(III) fluoride Americium(III) bromide Americium(III) iodide |
Other cations
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Plutonium(III) chloride Curium(III) chloride Europium(III) chloride |
| Americium(II) chloride | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
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Americium(III) chloride or Americium trichloride is the chemical compound composed of americium and chlorine with the formula AmCl3. This Actinide salt forms pink hexagonal crystals. In the solid state each americium atom has nine chlorine atoms as near neighbours, at approximately the same distance, in a tricapped trigonal prismatic configuration.[3][4]
The hexahydrate has a monocline crystal structure with: a = 970.2 pm, b = 656.7 pm and c = 800.9 pm; β = 93° 37'; space group: P2/n.[5]
Reactions
An americium(III) chloride electrorefining method has been investigated to separate mixtures of actinides, since the standard Gibbs free energy of formation of americium(III) chloride is much different than the rest of the actinide chlorides.[6] This can be used to remove americium from plutonium by melting the crude mixture together with salts such as sodium chloride.[7]
Properties
Americium trichloride is a pink salt that can be formed when Americium, reacts with three Chlorine atoms, to make . A way it can be made is by putting Americium dioxide into Hydrochloric acid.
![{\displaystyle {\mathrm {AmCl} {\vphantom {A}}_{\smash[{t}]{3}}}}](./_assets_/eb734a37dd21ce173a46342d1cc64c92/fafebabdc2699b6c4164fdd255c0451ff919779c.svg)
![{\displaystyle {\mathrm {AmO} {\vphantom {A}}_{\smash[{t}]{2}}{}+{}4\,\mathrm {HCl} {}\mathrel {\longrightarrow } {}\mathrm {AmCl} {\vphantom {A}}_{\smash[{t}]{3}}{}+{}2\,\mathrm {H} {\vphantom {A}}_{\smash[{t}]{2}}\mathrm {O} {}+{}\mathrm {Cl} }}](./_assets_/eb734a37dd21ce173a46342d1cc64c92/7940b239200d282891cd25cc2234adac2c11f8fa.svg)
It is a radioactive salt because Americium, is radioactive as a actinide and is thus toxic. Inhaling or ingesting can have fatal consequences. It melts at 715C as mentioned in this article.
Radioactive decay
As Americium decays into Neptunium,[8] it Turns into . The decay chain of Americium-241 into Neptunium Is as follows:
![{\displaystyle {\mathrm {NpCl} {\vphantom {A}}_{\smash[{t}]{3}}}}](./_assets_/eb734a37dd21ce173a46342d1cc64c92/81ebe6b432fd466de299fe6029813259649dd1ab.svg)
It also releases 59.5 keV (kilo electron volts) as a gamma ray.[8]
![{\displaystyle {{\vphantom {A}}_{\hphantom {95}}^{\hphantom {241}}{\mkern {-1.5mu}}{\vphantom {A}}_{{\vphantom {2}}{\llap {\smash[{t}]{95}}}}^{{\smash[{t}]{\vphantom {2}}}{\llap {241}}}\mathrm {Am} {}\mathrel {\longrightarrow } {}{\vphantom {A}}_{\hphantom {93}}^{\hphantom {237}}{\mkern {-1.5mu}}{\vphantom {A}}_{{\vphantom {2}}{\llap {\smash[{t}]{93}}}}^{{\smash[{t}]{\vphantom {2}}}{\llap {237}}}\mathrm {Np} {}+{}{\vphantom {A}}_{\hphantom {2}}^{\hphantom {4}}{\mkern {-1.5mu}}{\vphantom {A}}_{{\vphantom {2}}{\llap {\smash[{t}]{2}}}}^{{\smash[{t}]{\vphantom {2}}}{\llap {4}}}\mathrm {He} }}](./_assets_/eb734a37dd21ce173a46342d1cc64c92/d5766e396132f81eff4fbf3fc8e004e6d4547d98.svg)
Hazards
Americium-241, the most common isotope, does not pose a significant Radiological Hazard unless Inhaled or Ingested, as the alpha particles can cause various cancers. Its gamma radiation creates a significant external dose, so americium is handled in lead-lined gloveboxes.[8]
References
- ^ a b "Chemistry: Periodic Table: americium: compound data (americium (III) chloride)". WebElements. Retrieved 2008-06-24.
- ^ Perry, Dale L.; Phillips, Sidney L. (1995). Handbook of Inorganic Compounds. CRC Press. p. 15. ISBN 0-8493-8671-3. Retrieved 2008-06-25.
- ^ L. B. Asprey, T. K. Keenan, F. H. Kruse: "Crystal Structures of the Trifluorides, Trichlorides, Tribromides, and Triiodides of Americium and Curium", Inorg. Chem. 1965, 4 (7), 985–986; doi:10.1021/ic50029a013.
- ^ A. F. Wells: Structural Inorganic Chemistry 5th edition (1984) Oxford Science Publications, ISBN 0-19-855370-6.
- ^ John H. Burns, Joseph Richard Peterson: "The Crystal Structures of Americium Trichloride Hexahydrate and Berkelium Trichloride Hexahydrate", Inorg. Chem. 1971, 10 (1), 147–151; doi:10.1021/ic50095a029.
- ^ Nuclear Energy Agency (2001), Proceedings of the Workshop on Pyrochemical Separations, Avignon, France: OECD Publishing, pp. 276–277, ISBN 92-64-18443-0, retrieved 2008-06-24
- ^ Plutonium Processing In The Nuclear Weapons Complex, Diane Publishing, 1992, p. 21, ISBN 1-56806-568-X, retrieved 2008-06-24
- ^ a b c Clark, David. "United States of Americium". Los Alamos National Laboratory (LANL). Los Alamos National Laboratory. Retrieved 2026-02-28.