Neptunium (IV) fluoride

Crystal structure
__  Np 4+      __  F -
Crystal system	monoclinic
Space group	C 2 / c (No. 15)
Lattice parameters	a = 1264 pm b = 1070 pm c = 836 pm β = 126.4 °
General
Surname	Neptunium (IV) fluoride
other names	Neptunium tetrafluoride
Ratio formula	NpF 4
Brief description	green solid
External identifiers / databases
CAS number 14529-88-5 Wikidata Q1977882
properties
Molar mass	313.04 g mol −1
Physical state	firmly
density	6.8 g cm −3
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 .

Neptunium (IV) fluoride is a chemical compound made up of the elements neptunium and fluorine . It has the formula NpF ₄ and belongs to the fluoride class of substances .

presentation

Neptunium (IV) fluoride is produced by reacting neptunium (IV) oxide  (NpO ₂ ) with hydrogen fluoride  (HF) in an O ₂ stream at 500 ° 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.

${\displaystyle {\ce {NpO2 + O2 + 4 HF -> NpF4 + O2 + 2 H2O}}}$

Another  method of presentation is the oxidation of neptunium (III) fluoride (NpF ₃ ) with an oxygen-hydrogen fluoride mixture.

${\displaystyle {\ce {4 NpF3 + O2 + 4 HF -> 4 NpF4 + 2 H2O}}}$

properties

Physical Properties

Neptunium (IV) fluoride is a green solid and crystallizes in the monoclinic crystal system with the lattice parameters a  = 1264  pm , b  = 1070 pm, c  = 836 pm and β  = 126.4 °.

Chemical properties

Neptunium (IV) fluoride is reduced in the H ₂ stream to neptunium (III) fluoride  (NpF ₃ ):

${\displaystyle {\ce {2 NpF4 + H2 -> 2 NpF3 + 2 HF}}}$

Neptunium (IV) fluoride is converted into volatile neptunium hexafluoride  (NpF ₆ ) in a flow of fluorine gas at 500 ° C :

${\displaystyle {\ce {NpF4 + F2 -> NpF6}}}$

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 c d} C. Keller: The chemistry of Neptunium , in: Fortschr. chem. Forsch. , 1969/70 , 13/1 , p. 69.
2. ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1969.
3. ↑ Neptunium (IV) fluoride at www.webelements.com .
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. ↑ ^{a b} C. Keller: The chemistry of Neptunium , in: Fortschr. chem. Forsch. , 1969/70 , 13/1 , p. 67.
6. ^ Wissenschaft-Online-Lexika: Entry on “Neptuniumverbindungen” in the Lexikon der Chemie, accessed on April 7, 2010.
7. ↑ John G. Malm, Bernard Weinstock, E. Eugene Weaver: The Preparation and Properties of NpF ₆ ; a Comparison with PuF ₆ , in: J. Phys. Chem. , 1958 , 62  (12), pp. 1506-1508 ( doi : 10.1021 / j150570a009 ).

literature

• Zenko Yoshida, Stephen G. Johnson, Takaumi Kimura, John R. Krsul: Neptunium , 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. 699-812 ( doi : 10.1007 / 1-4020-3598-5_6 ).
• C. Keller: The chemistry of neptunium , in: Fortschr. chem. Forsch. , 1969/70 , 13/1 , pp. 1–124 ( doi : 10.1007 / BFb0051170 ).
• Gmelin's Handbook of Inorganic Chemistry , System No. 71, Transurane, Part C, pp. 104-107.