Uranium (V) fluoride

Crystal structure
	__ U 5+ __ F -
Crystal system	tetragonal
Space group	I 4 2 d (No. 122) (β); I 4 / m (No. 87) (α);
Lattice parameters	a = 1150 pm (β) ; c = 519.9 pm (β)
General
Surname	Uranium (V) fluoride
other names	Uranium pentafluoride
Ratio formula	UF 5
Brief description	pale yellow crystals
External identifiers / databases
EC number	237-405-9
ECHA InfoCard	100.033.991
PubChem	83723
Wikidata	Q417975
properties
Molar mass	333.02 g mol −1
Physical state	firmly
density	6.45 g cm −3 (β); 5.81 g cm −3 (α);
Melting point	348 ° C
Hazard and safety information
	; Radioactive
H and P phrases	H: 330-300-373-411
	P: ?
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Uranium (V) fluoride is a chemical compound consisting of the elements uranium and fluorine . It has the formula UF ₅ and belongs to the fluoride class of substances .

presentation

Uranium (V) fluoride is produced by reacting uranium (VI) chloride or uranium (V) chloride with anhydrous hydrogen fluoride .

{\ displaystyle \ mathrm {2 \ UCl_ {6} +10 \ HF \ longrightarrow 2 \ UF_ {5} +10 \ HCl + Cl_ {2}}}

{\ displaystyle \ mathrm {2 \ UCl_ {5} +10 \ HF \ longrightarrow 2 \ UF_ {5} +10 \ HCl}}

The comproportioning of uranium (IV) fluoride and uranium (VI) fluoride is also possible

{\ displaystyle \ mathrm {UF_ {4} + UF_ {6} \ longrightarrow 2 \ UF_ {5}}}

or the fluorination of uranium (IV) fluoride.

{\ displaystyle \ mathrm {2 \ UF_ {4} + F_ {2} \ longrightarrow 2 \ UF_ {5}}}

It is also possible to produce it by reducing uranium (VI) fluoride either with hydrogen bromide or with sulfur dioxide at 160 ° C.

properties

Uranium (V) fluoride exists in two modifications , the low-temperature β-modification and the high-temperature α-modification. The transition temperature is 130 ° C. The β-modification is pale yellow and has a tetragonal crystal structure with the space group I 4 2 d (space group no. 122) and the lattice parameters a = 1150 pm and c = 519.8 pm. The α-modification also has a tetragonal crystal structure with the space group I 4 / m (No. 87) and the lattice parameters a = 651.2 pm and c = 446.3 pm. It is in vacuum above 500 ° C sublimable , wherein from 150 ° C a disproportionation begins. It forms pale blue to pale gray crystals and melts (under UF ₆ pressure) at 348 ° C. The compound consists of UF ₅ units and forms linear chains through fluorine bridges. The monomer has a fluctuating geometry between D _3h and C _4v . Template: room group / 122 Template: room group / 87

use

Uranium (V) fluoride plays a role in the laser enrichment of uranium (VI) fluoride . Here, the molecule containing ²³⁵ U is first selectively excited by a first laser before a fluorine atom is split off by a second laser. The resulting solid ²³⁵ UF ₅ can easily be filtered out of the gas. The ²³⁸ UF ₆ is not converted, so that a simple separation of the isotopes takes place. After an initial euphoria about the advantages of this process compared to conventional, established enrichment processes, later there was again greater skepticism about the industrial feasibility.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Georg Brauer (Ed.), With the collaboration of Marianne Baudler u. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , pp. 1203-1204.
↑ ^a ^b David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 89th edition. (Internet version: 2009), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-17.
↑ Entry on uranium compounds in the GESTIS substance database of the IFA , accessed on February 1, 2016 (JavaScript required)
↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry uranium compounds with the exception of those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA) , accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ The hazards emanating from radioactivity do not belong to the properties to be classified according to the GHS labeling.
↑ PG Eller, AC Larson, JR Peterson, DD Ensor, JP Young: "Crystal structures of α-UF ₅ and U ₂ F ₉ and spectral characterization of U ₂ F ₉ ", in: Inorganica Chimica Acta , 1979 , 37 (2 ), Pp. 129-133 ( doi : 10.1016 / S0020-1693 (00) 95530-0 ).
↑ JC Taylor, AB Waugh: "Neutron diffraction study of β-uranium pentafluoride between 77 and 403 K", in: Journal of Solid State Chemistry , 1980 , 35 (2), pp. 137-147 ( doi : 10.1016 / 0022- 4596 (80) 90485-5 , bibcode : 1980JSSCh..35..137T ).
^ CJ Howard, JC Taylor, AB Waugh: "Crystallographic Parameters in α-UF ₅ and U ₂ F ₉ by Multiphase Refinement of High-Resolution Neutron Powder Data", in: Journal of Solid State Chemistry , 1982 , 45 , p. 396 -398 ( doi : 10.1016 / 0022-4596 (82) 90185-2 ).
↑ J. Onoe, H. Nakamatsu, T. Mukoyama, R. Sekine, H. Adachi, K. Takeuchi: “Structure and Bond Nature of the UF ₅ Monomer”, in: Inorganic Chemistry , 1997 , 36 (9), p 1934-1938 ( doi : 10.1021 / ic961237s ).
↑ Rainer Köthe: "Cheap fuel for nuclear power plants" , Die Zeit , 25/1975 (June 13, 1975) ( PDF ).

literature

Ingmar Grenthe, Janusz Drożdżynński, Takeo Fujino, Edgar C. Buck, Thomas E. Albrecht-Schmitt, Stephen F. Wolf: Uranium , 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. 253-698 ( doi : 10.1007 / 1-4020-3598-5_5 ).
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.

[brauer-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Georg Brauer (Ed.), With the collaboration of Marianne Baudler u. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , pp. 1203-1204.

[CRC-2] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 89th edition. (Internet version: 2009), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-17.

[GESTIS-3] Entry on uranium compounds in the GESTIS substance database of the IFA , accessed on February 1, 2016 (JavaScript required)

[CLP_100.240.790-4] Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry uranium compounds with the exception of those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA) , accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[5] The hazards emanating from radioactivity do not belong to the properties to be classified according to the GHS labeling.

[Eller_1979-6] PG Eller, AC Larson, JR Peterson, DD Ensor, JP Young: "Crystal structures of α-UF ₅ and U ₂ F ₉ and spectral characterization of U ₂ F ₉ ", in: Inorganica Chimica Acta , 1979 , 37 (2 ), Pp. 129-133 ( doi : 10.1016 / S0020-1693 (00) 95530-0 ).

[Taylor_1980-7] JC Taylor, AB Waugh: "Neutron diffraction study of β-uranium pentafluoride between 77 and 403 K", in: Journal of Solid State Chemistry , 1980 , 35 (2), pp. 137-147 ( doi : 10.1016 / 0022- 4596 (80) 90485-5 , bibcode : 1980JSSCh..35..137T ).

[Howard_1982-8] CJ Howard, JC Taylor, AB Waugh: "Crystallographic Parameters in α-UF ₅ and U ₂ F ₉ by Multiphase Refinement of High-Resolution Neutron Powder Data", in: Journal of Solid State Chemistry , 1982 , 45 , p. 396 -398 ( doi : 10.1016 / 0022-4596 (82) 90185-2 ).

[Onoe_1997-9] J. Onoe, H. Nakamatsu, T. Mukoyama, R. Sekine, H. Adachi, K. Takeuchi: “Structure and Bond Nature of the UF ₅ Monomer”, in: Inorganic Chemistry , 1997 , 36 (9), p 1934-1938 ( doi : 10.1021 / ic961237s ).

[10] Rainer Köthe: "Cheap fuel for nuclear power plants" , Die Zeit , 25/1975 (June 13, 1975) ( PDF ).