Americium (III) fluoride

Crystal structure
__ On 3+      __ F -
Crystal system	hexagonal
Space group	P 6 3 / mmc (No. 194)
Lattice parameters	a = 704.4 pm c = 722.5 pm
Coordination numbers	On [9], F [3]
General
Surname	Americium (III) fluoride
other names	Americium trifluoride
Ratio formula	AmF 3
Brief description	pink hexagonal crystals
External identifiers / databases
CAS number 13708-80-0 PubChem 21493614 Wikidata Q467651
properties
Molar mass	300.06 g mol −1
Physical state	firmly
density	9.53 g cm −3
Melting point	1393 ° C
Hazard and safety information
Radioactive
GHS hazard labeling no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Americium (III) fluoride is a fluoride of the artificial element and actinoid americium with the empirical formula AmF ₃ . Americium occurs in this salt in the +3 oxidation state.

presentation

Americium (III) fluoride can be produced by reacting an aqueous americium solution with fluoride salts in a weakly acidic environment .

${\displaystyle {\ce {Am^3+(aq) + 3 F^- (aq) -> AmF3 (s) v}}}$

In the anhydrous state, it can also be produced from americium (III) hydroxide at 600–750 ° C in a 1: 1 gas mixture of HF / O ₂ :

${\displaystyle {\ce {Am(OH)3 + 3 HF -> AmF3 + 3 H2O}}}$

properties

Americium (III) fluoride is a pink solid that melts at 1393 ° C. It crystallizes in the lanthanum fluoride structure with the lattice parameters a  = 704.4  pm and c  = 722.5 pm. Each americium core is surrounded by nine fluorine cores in a distorted, triple-capped trigonal-prismatic structure.

use

Metallic americium can be obtained by reduction from americium (III) fluoride. For this purpose, this is caused to react with elemental barium in reaction apparatuses made of tantalum and tungsten in an environment free of water and oxygen .

${\displaystyle {\ce {2 AmF3 + 3 Ba -> 2 Am + 3 BaF2}}}$

safety instructions

Classifications according to the CLP regulation are not available because they only include chemical hazard and play a completely subordinate role compared to the hazards based on radioactivity . The latter also only applies if the amount of substance involved is relevant.

Individual evidence

1. ↑ ^{a b} L. B. Asprey, TK Keenan, FH Kruse: Crystal Structures of the Trifluorides, Trichlorides, Tribromides, and Triiodides of Americium and Curium , in: Inorg. Chem. , 1965 , 4  (7), pp. 985-986 ( doi: 10.1021 / ic50029a013 ).
2. ↑ Americium (III) fluoride at www.webelements.com.
3. ^ ^{A b} A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1969.
4. ↑ The hazards emanating from radioactivity do not belong to the properties to be classified according to the GHS labeling. With regard to other hazards, this substance has either not yet been classified or a reliable and citable source has not yet been found.
5. ↑ Sherman Fried: The Preparation of Anhydrous Americium Compounds , in: J. Am. Chem. Soc. , 1951 , 73  (1), pp. 416-418 ( doi: 10.1021 / ja01145a135 ).
6. ↑ Gmelin's Handbook of Inorganic Chemistry , System No. 71, Transurane, Part C, p. 102.
7. ^ Edgar F. Westrum, Jr., LeRoy Eyring: The Preparation and Some Properties of Americium Metal , in: J. Am. Chem. Soc. , 1951 , 73  (7), pp. 3396-3398 ( doi: 10.1021 / ja01151a116 ).
8. ↑ Gmelin's Handbook of Inorganic Chemistry , System No. 71, Transurane, Part B 1, pp. 57-67.

literature

• Wolfgang H. Runde, Wallace W. Schulz: Americium , in: Lester R. Morss, Norman M. Edelstein, Jean Fuger (Eds.): The Chemistry of the Actinide and Transactinide Elements , Springer, Dordrecht 2006; ISBN 1-4020-3555-1 , pp. 1265-1395 ( doi : 10.1007 / 1-4020-3598-5_8 ).