Tungsten oxytetrafluoride
{{chembox
| Watchedfields = changed
| verifiedrevid = 428739426
| Name = Tungsten(VI) oxytetrafluoride
| ImageFile = WOF4 structure.svg
| ImageName = Tungsten(VI) oxytetrafluoride
| OtherNames =
| Section1 = {{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|??}}
| CASNo = 13520-79-1
| ChemSpiderID = 10329780
| PubChem = 139487
| PubChem_Comment = formula error
| StdInChI = 1S/4FH.O.W/h4*1H;;/q;;;;;+4/p-4
| StdInChIKey = UZQPVNLRTKDHNK-UHFFFAOYSA-J
| SMILES = O=[W](F)(F)(F)F
}}
| Section2 = {{Chembox Properties
| Formula = WOF4
| MolarMass = 275.83 g/mol
| Appearance = colourless crystals{{cite book | last1=Perry | first1=Dale L. | last2=Phillips | first2=Sidney L. | title=Handbook of inorganic compounds | publisher=CRC Press | publication-place=Boca Raton | date=1995 | isbn=0-8493-8671-3 | oclc=32347397 |page=428}}
|SolubleOther=soluble in chloroform
sparingly soluble in carbon disulfide
}}
| Section3 = {{Chembox Structure
| CrystalStruct = monoclinic
}}
| Section7 = {{Chembox Hazards
}}
| Section8 = {{Chembox Related
| OtherAnions = Tungsten(VI) oxytetrachloride
Tungsten(VI) oxytetrabromide
| OtherCations =
}}
}}
Tungsten oxytetrafluoride is an inorganic compound with the formula WOF4. It is a colorless diamagnetic solid. The compound is one of many oxides of tungsten. It is usually encountered as product of the partial hydrolysis of tungsten hexafluoride.
Structure
As confirmed by X-ray crystallography, WOF4 crystallizes as a tetramer. The oxides are terminal, and four of the fluorides are bridging.{{cite journal |doi=10.1021/acs.inorgchem.0c02783 |title=Reactions of Molybdenum and Tungsten Oxide Tetrafluoride with Sulfur(IV) Lewis Bases: Structure and Bonding in [WOF4]4, MOF4(OSO), and [SF3][M2O2F9] (M = Mo, W) |year=2020 |last1=Turnbull |first1=Douglas |last2=Chaudhary |first2=Praveen |last3=Leenstra |first3=Dakota |last4=Hazendonk |first4=Paul |last5=Wetmore |first5=Stacey D. |last6=Gerken |first6=Michael |journal=Inorganic Chemistry |volume=59 |issue=23 |pages=17544–17554 |pmid=33200611 |s2cid=226989898 }} Its structure is similar to those for niobium pentafluoride and tantalum pentafluoride. In contrast, molybdenum oxytetrafluoride adopts a polymeric structure, although again the fluorides bridge and the oxides are terminal.{{cite journal |doi=10.1039/j19680002503 |title=Fluoride crystal structures. Part II. Molybdenum oxide tetrafluoride |year=1968 |last1=Edwards |first1=A. J. |last2=Steventon |first2=B. R. |journal=Journal of the Chemical Society A: Inorganic, Physical, Theoretical |page=2503 }}
In the gas state, this molecule is a monomer.{{cite book | last=Johnson | first=B. F. G. | title=Inorganic chemistry of the transition elements. Volume 4, A review of the literature published between October 1973 and September 1974 | publisher=Chemical Society | publication-place=London | date=1976 | isbn=978-1-84755-645-5 | oclc=820579758 |page=138}} It can form complexes with acetonitrile and other compounds.{{cite journal | last1=Levason | first1=William | last2=Reid | first2=Gillian | last3=Zhang | first3=Wenjian | title=Coordination complexes of the tungsten(VI) oxide fluorides WOF4 and WO2F2 with neutral oxygen- and nitrogen-donor ligands | journal=Journal of Fluorine Chemistry | publisher=Elsevier BV | volume=184 | year=2016 | issn=0022-1139 | doi=10.1016/j.jfluchem.2016.02.003 | pages=50–57| doi-access=free }}{{cite journal | last1=Arnaudet | first1=Lucile | last2=Bougon | first2=Roland | last3=Charpin | first3=Pierrette | last4=Isabey | first4=Jacques | last5=Lance | first5=Monique | last6=Nierlich | first6=Martine | last7=Vigner | first7=Julien | title=Preparation, characterization, and crystal structure of the adducts WOF4.nC5H5N (n = 1, 2) | journal=Inorganic Chemistry | publisher=American Chemical Society (ACS) | volume=28 | issue=2 | year=1989 | issn=0020-1669 | doi=10.1021/ic00301a020 | pages=257–262}}
Preparation
Tungsten(VI) oxytetrafluoride can be synthesized by the reaction of fluorine and tungsten trioxide.
It can also be obtained by treating tungsten with a mixture of oxygen and fluorine at high temperatures. Partial hydrolysis of tungsten hexafluoride will also produce WOF4.{{cite book | last=Mendicino | first=L. | author2=Electrochemical Society. Dielectric Science and Technology Division | author3=Electrochemical Society. Meeting | author4=Symposium on Environmental Issues with Materials and Processes in the Electronics and Semiconductor Industries | title=Environmental issues with materials and processes for the electronics and semiconductor industries : proceedings of the fourth international symposium | publisher=Electrochemical Society | publication-place=Pennington, NJ | date=2001 | isbn=1-56677-312-1 | oclc=48710248 |page=180}}
:{{chem2|WF6 + H2O -> WOF4 + 2 HF}}
The reaction of tungsten(VI) oxytetrachloride and hydrogen fluoride will also produce WOF4.{{cite book | last1=Lassner | first1=Erik | last2=Schubert | first2=Wolf-Dieter | title=Tungsten : Properties, Chemistry, Technology of the Element, Alloys, and Chemical Compounds | publication-place=Boston, MA | date=1999 | isbn=1-4615-4907-8 | oclc=1113605323 |page=168}}
:{{chem2|WOCl4 + 4HF -> WOF4 + 4 HCl}}
WOF4 can also prepared by the reaction of lead(II) fluoride and tungsten trioxide at 700 °C.
:{{chem2|2 PbF2 + WO3 -> WOF4 + 2 PbO}}
Tungsten(VI) oxytetrafluoride hydrolyzes into tungstic acid.
:{{chem2|WOF4 + 2 H2O -> WO3 + 4 HF}}