Molybdenum hexafluoride

Names
IUPAC names

molybdenum(VI) fluoride

Other names

molybdenum hexafluoride

Identifiers

CAS Number

* 7783-77-9 Y

3D model (JSmol)

* Interactive image

ChemSpider |

* 74199

ECHA InfoCard | 100.029.114
EC Number |

* 232-026-5

PubChem CID

* 82219

UNII |

* ZLT5J123W3 Y

CompTox Dashboard (EPA)

* DTXSID0064834

InChI

* InChI=1S/6FH.Mo/h6*1H;/q;;;;;;+6/p-6

SMILES

* F[Mo](F)(F)(F)(F)F

Properties

Chemical formula

| MoF6
Molar mass | 209.93 g/mol
Appearance  | white crystals[1] or colorless liquid
hygroscopic
Density | 3.50 g/cm3[2]
Melting point | 17.5 °C (63.5 °F; 290.6 K)[1]
Boiling point | 34.0 °C (93.2 °F; 307.1 K)[1]

Solubility in water

| hydrolyzes

Magnetic susceptibility (χ)

| −26.0·10−6 cm3/mol
Structure

Crystal structure

| Orthorhombic, oP28

Space group

| Pnma, No. 62

Coordination geometry

| octahedral (Oh)

Dipole moment

| 0
Related compounds

Other cations

| Tungsten hexafluoride
Uranium hexafluoride
Molybdenum(VI) chloride

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

N verify (what is YN ?)

Infobox references

Chemical compound

Molybdenum hexafluoride, also molybdenum(VI) fluoride, is the inorganic compound with the formula MoF6. It is the highest fluoride of molybdenum. It is a colourless solid and melts just below room temperature and boils in 34 °C.[3] It is one of the seventeen known binary hexafluorides.

## Synthesis[edit]

Molybdenum hexafluoride is made by direct reaction of molybdenum metal in an excess of elemental fluorine:[2]

Mo \+ 3 F
2 → MoF

The compound hydrolyzes easily,[4] and typical impurities are MoO2F2 and MoOF4.[5]

## Description[edit]

At −140 °C, it crystallizes in the orthorhombic space group Pnma. Lattice parameters are a = 9.394 Å, b = 8.543 Å, and c = 4.959 Å. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 3.50 g·cm−3.[2] The fluorine atoms are arranged in the hexagonal close packing.[6]

In liquid and gas phase, MoF6 adopt octahedral molecular geometry with point group Oh. The Mo–F bond length is 1.817 Å.[2]

## Applications[edit]

Molybdenum hexafluoride has few uses. In the nuclear industry, MoF6 occurs as an impurity in uranium hexafluoride since molybdenum is a fission product of uranium.

The semiconductor industry constructs various integrated circuits through chemical vapor deposition of molybdenum hexafluoride.[4] In some cases, the deposited molybdenum is an impurity in the intended tungsten hexafluoride. MoF6 can be removed by reduction of a WF6-MoF6 mixture with any of a number of elements including hydrogen iodide at moderately elevated temperature.[7][8]

## References[edit]

1. ^ a b c CRC Handbook of Chemistry and Physics, 90th Edition, CRC Press, Boca Raton, Florida, 2009, ISBN 978-1-4200-9084-0, Section 4, Physical Constants of Inorganic Compounds, p. 4-85.
2. ^ a b c d T. Drews, J. Supeł, A. Hagenbach, K. Seppelt: "Solid State Molecular Structures of Transition Metal Hexafluorides", in: Inorganic Chemistry, 2006, 45 (9), S. 3782–3788; doi:10.1021/ic052029f; PMID 16634614
3. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
4. ^ a b Meshri, Dayal T. (2000), "Fluorine compounds, inorganic, molybdenum", Kirk-Othmer Encyclopedia of Chemical Technology, New York: John Wiley, doi:10.1002/0471238961.1315122513051908.a01, ISBN 9780471238966
5. ^ W. Kwasnik "Molybdenum(VI) Fluoride" Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 259.
6. ^ J. H. Levy, J. C Taylor, A. B. Waugh: "Neutron Powder Structural Studies of UF6, MoF6 and WF6 at 77 K", in: Journal of Fluorine Chemistry, 1983, 23 (1), pp. 29–36; doi:10.1016/S0022-1139(00)81276-2.
7. ^ US-Patent 5234679: Method of Refining Tungsten Hexafluoride Containing Molybdenum Hexafluoride as an Impurity Archived 2011-06-12 at the Wayback Machine, 10 August 1993
8. ^ US-Patent 6896866: Method for Purification of Tungsten Hexafluoride Archived 2011-06-12 at the Wayback Machine, 24 May 2005.

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Binary hexafluorides

Known binary hexafluorides|

| Chalcogen binary hexafluorides|

* SF6
* SeF6
* TeF6
* PoF6

|

Noble gas binary hexafluorides|

* XeF6

Transition metal binary hexafluorides|

* MoF6
* TcF6
* RuF6
* RhF6
* WF6
* ReF6
* OsF6
* IrF6
* PtF6

Actinide binary hexafluorides|

* UF6
* NpF6
* PuF6

Predicted binary hexafluorides|

| Noble gas binary hexafluorides|

* KrF6
* RnF

|

Transition metal binary hexafluorides|

* CrF6
* PdF6
* AuF6

Actinide binary hexafluorides|

* AmF6
* CmF6
* EsF6

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Molybdenum compounds

Mo(0)|

* Mo(CO)6
* Mo3P

Mo(II)|

* MoBr2
* MoCl2
* MoI2
* MoP2
* MoSi2

Mo(III)|

* MoBr3
* MoCl3
* MoI3
* Mo2O3
* Mo2(OtBu)6
* MoP

Mo(IV)|

* MoBr4
* MoCl4
* MoF4
* MoO2
* MoS2
* MoSe2
* MoTe2

Mo(V)|

* MoCl5
* MoF5
* Mo2O5

Mo(VI)|

* Molybdates
* Molybdic acid
* MoO3
* MoCl6
* MoOF4
* MoOCl4
* MoF2O2
* MoO2Cl2
* MoF6
* MoS3
* MoAs2

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Salts and covalent derivatives of the fluoride ion

| HF |  |  |  | ?HeF2

|
|
|
|

LiF | BeF2 | BF
BF3
B2F4
+BO3 | CF4
CxFy
+CO3 | NF3
FN3
N2F2

N2F4
NF2
?NF5 | OF2
O2F2

O3F2
O4F2
?OF4 | F2 | Ne
NaF | MgF2 | AlF
AlF3 | SiF4 | P2F4
PF3
PF5 | S2F2
SF2
S2F4
SF3
SF4
S2F10
SF6
+SO4 | ClF
ClF3
ClF5 | ?ArF2
?ArF4
KF | CaF
CaF2 |  | ScF3 | TiF2
TiF3
TiF4 | VF2
VF3
VF4
VF5 | CrF2
CrF3
CrF4
CrF5
?CrF6 | MnF2
MnF3
MnF4
?MnF5 | FeF2
FeF3
FeF4 | CoF2
CoF3
CoF4 | NiF2
NiF3
NiF4 | CuF
CuF2
?CuF3 | ZnF2 | GaF2
GaF3 | GeF2
GeF4 | AsF3
AsF5 | Se2F2
SeF4
SeF6
+SeO3 | BrF
BrF3
BrF5 | KrF2
?KrF4
?KrF6
RbF | SrF
SrF2 |  | YF3 | ZrF3
ZrF4 | NbF4
NbF5 | MoF4
MoF5
MoF6 | TcF4
TcF

TcF6 | RuF3
RuF

RuF5
RuF6 | RhF3
RhF4
RhF5
RhF6 | PdF2
Pd[PdF6]
PdF4
?PdF6 | Ag2F
AgF
AgF2
AgF3 | CdF2 | InF
InF3 | SnF2
SnF4 | SbF3
SbF5 | TeF4
TeF6
+TeO3 | IF
IF3
IF5
IF7
+IO3 | XeF2
XeF4
XeF6
?XeF8
CsF | BaF2 |  | LuF3 | HfF4 | TaF5 | WF4
WF5
WF6 | ReF4
ReF5
ReF6
ReF7 | OsF4
OsF5
OsF6
?OsF

?OsF
8 | IrF2
IrF3
IrF4
IrF5
IrF6 | PtF2
Pt[PtF6]
PtF4
PtF5
PtF6 | AuF
AuF3
Au2F10
?AuF6
AuF5•F2 | Hg2F2
HgF2
?HgF4 | TlF
TlF3 | PbF2
PbF4 | BiF3
BiF5 | ?PoF2
PoF4
PoF6 | AtF
?AtF3
?AtF5 | RnF2
?RnF

?RnF

FrF  | RaF2 |  | LrF3 | Rf  | Db  | Sg  | Bh  | Hs  | Mt  | Ds  | Rg  | Cn  | Nh  | Fl  | Mc  | Lv  | Ts  | Og
| ↓  |  |
| LaF3 | CeF3
CeF4 | PrF3
PrF4 | NdF2
NdF3
NdF4 | PmF3 | SmF2
SmF3 | EuF2
EuF3 | GdF3 | TbF3
TbF4 | DyF2
DyF3
DyF4 | HoF3 | ErF3 | TmF2
TmF3 | YbF2
YbF3
AcF3 | ThF4 | PaF4
PaF5 | UF3
UF4
UF5
UF6 | NpF3
NpF4
NpF5
NpF6 | PuF3
PuF4
PuF5
PuF6 | AmF2
AmF3
AmF4
AmF6 | CmF3
CmF4
CmF6 | BkF3
BkF
4 | CfF3
?CfF4 | EsF3
EsF4
?EsF6 | Fm  | Md  | No
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