Molybdenum (VI) fluoride

Structural formula
General
Surname	Molybdenum (VI) fluoride
other names	Molybdenum hexafluoride
Molecular formula	MoF 6
Brief description	colorless to yellowish liquid with a pungent odor
External identifiers / databases
EC number	232-026-5
ECHA InfoCard	100.029.114
PubChem	82219
Wikidata	Q411592
properties
Molar mass	209.93 g mol −1
Physical state	liquid
density	3.50 g cm −3 (−140 ° C); 2.54 g cm −3 (19 ° C);
Melting point	17.5 ° C
boiling point	34.0 ° C
solubility	reacts with water
safety instructions
H and P phrases	H: 330-314
	EUH: 032
	P: 280-301 + 330 + 331-303 + 361 + 353-304 + 340-310-305 + 351 + 338
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Molybdenum (VI) fluoride (MoF ₆ ), often also molybdenum hexafluoride , is a chemical compound of the elements molybdenum and fluorine and belongs to the group of hexafluorides . It is the highest fluoride in molybdenum. Since molybdenum is a fission product of uranium , molybdenum hexafluoride occurs as an impurity in uranium hexafluoride . Furthermore, due to the chemical similarity of molybdenum and tungsten, it is also contained as an impurity in tungsten hexafluoride . It can be removed from this by reducing a WF ₆ -MoF ₆ mixture with any element, including molybdenum, at a moderately elevated temperature.

presentation

Molybdenum hexafluoride is produced by direct conversion of the metal in an excess of elemental fluorine (F ₂ ).

{\ displaystyle {\ ce {Mon + 3 F2 -> MoF6}}}

properties

Molybdenum hexafluoride is a moisture-sensitive, colorless to yellowish liquid with a pungent odor at room temperature, which solidifies to a white crystalline solid at 17.5 ° C or boils at 34.0 ° C. It crystallizes in the orthorhombic crystal system (measured at −140 ° C) in the space group Pnma (No. 62) with the lattice parameters a = 939.4 pm , b = 854.3 pm and c = 495.9 pm and four formula units per unit cell with a calculated density of 3.50 g · cm ⁻³ . The fluorine atoms occupy the hexagonal closest packing of spheres . The MoF ₆ molecule is octahedral ( O _h ); the Mo – F bond length is 181.7 pm. Template: room group / 62

Individual evidence

↑ ^a ^b ^c ^d ^e ^f Entry on molybdenum (VI) fluoride in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .
↑ ^a ^b ^c T. Drews, J. Supeł, A. Hagenbach, K. Seppelt: "Solid State Molecular Structures of Transition Metal Hexafluorides", in: Inorganic Chemistry , 2006 , 45 (9), pp. 3782-3788 ( doi : 10.1021 / ic052029f ; PMID 16634614 ).
↑ ^a ^b ^c Georg Brauer (ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 267.
↑ Patent US5234679 : Method of Refining Tungsten Hexafluoride Containing Molybdenum Hexafluoride as an Impurity. Published August 10, 1993 , Inventors: TAKASHI SUENAGA, MITSUYA OHASHI, TAKASHI YONEDA, YOSHIYUKI KOBAYASHI. ‌
↑ Patent US6896866 : Method for Purification of Tungsten Hexafluoride. Published on May 15, 2003 , Inventors: HIROHISA KIKUYAMA, MASAHIDE WAKI, KAZUYUKI FUJIMOTO, YOSHINORI NAKAGAWA. ‌
↑ 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. 4-77.
↑ JH Levy, J. C Taylor, AB Waugh: "Neutron Powder Structural Studies of UF ₆ , MoF ₆ and WF ₆ at 77 K", in: Journal of Fluorine Chemistry , 1983 , 23 (1), pp. 29-36 ( doi : 10.1016 / S0022-1139 (00) 81276-2 ).

literature

Gmelin's Handbook of Inorganic Chemistry , System No. 53, Molybdenum, Part A, pp. 150-151; Part B 5, pp. 117-182.

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f Entry on molybdenum (VI) fluoride in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .

[D_BLOCK_XF6-2] T. Drews, J. Supeł, A. Hagenbach, K. Seppelt: "Solid State Molecular Structures of Transition Metal Hexafluorides", in: Inorganic Chemistry , 2006 , 45 (9), pp. 3782-3788 ( doi : 10.1021 / ic052029f ; PMID 16634614 ).

[brauer-3] Georg Brauer (ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 267.

[4] Patent US5234679 : Method of Refining Tungsten Hexafluoride Containing Molybdenum Hexafluoride as an Impurity. Published August 10, 1993 , Inventors: TAKASHI SUENAGA, MITSUYA OHASHI, TAKASHI YONEDA, YOSHIYUKI KOBAYASHI. ‌

[5] Patent US6896866 : Method for Purification of Tungsten Hexafluoride. Published on May 15, 2003 , Inventors: HIROHISA KIKUYAMA, MASAHIDE WAKI, KAZUYUKI FUJIMOTO, YOSHINORI NAKAGAWA. ‌

[CRC_HANDBOOK_MoF6-6] 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. 4-77.

[7] JH Levy, J. C Taylor, AB Waugh: "Neutron Powder Structural Studies of UF ₆ , MoF ₆ and WF ₆ at 77 K", in: Journal of Fluorine Chemistry , 1983 , 23 (1), pp. 29-36 ( doi : 10.1016 / S0022-1139 (00) 81276-2 ).