Plutonium (IV) fluoride

Crystal structure
__  Pu 4+      __  F -
Crystal system	monoclinic
Space group	C 2 / c (No. 15)
Lattice parameters	a = 1261 pm b = 1057 pm c = 827 pm β = 126.16 °
General
Surname	Plutonium (IV) fluoride
other names	Plutonium tetrafluoride
Ratio formula	PuF 4
Brief description	red-brown monoclinic crystals
External identifiers / databases
CAS number 13709-56-3 PubChem 139558 Wikidata Q411484
properties
Molar mass	320.09 g mol −1
Physical state	firmly
density	7.1 g cm −3
Melting point	1037 ° C
Hazard and safety information
Radioactive
GHS hazard labeling no classification available
Thermodynamic properties
ΔH f 0	−425 ± 8 kcal mol −1
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Plutonium (IV) fluoride is a chemical compound made up of the elements plutonium and fluorine . It has the formula PuF ₄ and belongs to the fluoride class of substances . It is subject to the Nuclear Non-Proliferation Treaty .

presentation

Plutonium (IV) fluoride is produced by reacting plutonium dioxide  (PuO ₂ ) or plutonium (III) fluoride  (PuF ₃ ) with hydrogen fluoride  (HF) in an O ₂ stream at 450 to 600 ° C. The main purpose of the oxygen here is to avoid a reduction of the product by small amounts of hydrogen, which are mostly found in the HF gas.

${\displaystyle {\ce {PuO2 + O2 + 4 HF -> PuF4 + O2 + 2 H2O}}}$

${\displaystyle {\ce {4 PuF3 + O2 + 4 HF -> 4 PuF4 + 2 H2O}}}$

Laser irradiation of plutonium hexafluoride at a wavelength below 520 nm causes it to decompose into plutonium (V) fluoride and fluorine; if irradiation is continued, plutonium (IV) fluoride is obtained.

properties

Plutonium (IV) fluoride is a red-brown crystalline solid that melts at 1037 ° C. It crystallizes in the monoclinic crystal system with the lattice parameters a  = 1261  pm , b  = 1057 pm, c  = 827 pm and β  = 126.16 °.

safety instructions

Classifications according to the CLP regulation are not available, although the chemical toxicity is known. The dangers based on radioactivity are important , provided that the amount of substance involved is relevant.

Individual evidence

1. ^ ^{A b c d} W. H. Zachariasen: "Crystal Chemical Studies of the 5f-Series of Elements. XII. New Compounds Representing Known Structure Types ", in: Acta Crystallographica , 1949 , 2 , pp. 388-390 ( doi : 10.1107 / S0365110X49001016 ).
2. ↑ ^{a b} David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Properties of the Elements and Inorganic Compounds, pp. 4-81.
3. ↑ ^{a b c} Gmelin's Handbook of Inorganic Chemistry , System No. 71, Transurane, Part C, pp. 104-107.
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. ↑ www.freepatentsonline.com: Photochemical Preparation of Plutonium Pentafluoride ( PDF ).

literature

• David L. Clark, Siegfried S. Hecker , Gordon D. Jarvinen, Mary P. Neu: Plutonium , 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. 813-1264 ( doi : 10.1007 / 1-4020-3598-5_7 ).