Americium(III) chloride explained

Americium(III) chloride or americium trichloride is the chemical compound composed of americium and chlorine with the formula AmCl₃. This 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.^{[1] [2]}

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.^[3]

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.This can be used to remove americium from plutonium by melting the crude mixture together with salts such as sodium chloride.

Notes and References

1. 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; .
2. A. F. Wells: Structural Inorganic Chemistry 5th edition (1984) Oxford Science Publications, .
3. John H. Burns, Joseph Richard Peterson: "The Crystal Structures of Americium Trichloride Hexahydrate and Berkelium Trichloride Hexahydrate", Inorg. Chem. 1971, 10 (1), 147–151; .