Molybdenum difluoride dioxide
{{Chembox
| ImageFile = MoO2F2monomer.svg
| ImageSize =140
| ImageAlt =
| IUPACName =
| OtherNames = molybdenum dioxide difluoride
|Section1={{Chembox Identifiers
| CASNo = 13824-57-2
| CASNo_Comment =
| ChEBI =
| Gmelin =
| PubChem =
| StdInChI=1S/2FH.Mo.2O/h2*1H;;;/q;;+2;;/p-2
| StdInChIKey=RMUNMMZEBAMTER-UHFFFAOYSA-L
| SMILES = O=[Mo](F)(F)=O
}}
|Section2={{Chembox Properties
| Formula = {{chem2|MoF2O2}}
| Mo = 1|O=2|F=2
| Appearance = white solid
| Density = 3.82 g/cm3
| MeltingPt =
| MeltingPt_notes =
| BoilingPt =
| BoilingPt_notes =
| Solubility = }}
|Section3={{Chembox Hazards
| MainHazards =
| FlashPt =
| AutoignitionPt = }}
}}
Molybdenum difluoride dioxide is the inorganic compound with the formula {{chem2|MoF2O2|auto=1}}. It is a white, diamagnetic, volatile solid.{{Greenwood&Earnshaw2nd|page=1023}}
Structure
Gaseous molybdenum difluoride dioxide is a tetrahedral molecule.{{cite journal |doi=10.1021/ic50070a020 |title=Synthesis and Structure of Four- and Five-Coordinated Gaseous Oxohalides of Molybdenum(VI) and Tungsten(VI) |year=1968 |last1=Ward |first1=Brian G. |last2=Stafford |first2=Fred E. |journal=Inorganic Chemistry |volume=7 |issue=12 |pages=2569–2573}} According to X-ray crystallography, the solid is a coordination polymer consisting of trigonal primatic chains of made by linking {{chem2|Mo3F6O6}} monomers. The fluoride and oxide positions are disordered.{{cite journal |doi=10.1021/ic1000864 |title=Molybdenum Difluoride Dioxide, MoO2F2 |year=2010 |last1=Shorafa |first1=Hashem |last2=Ficicioglu |first2=Halil |last3=Tamadon |first3=Farhad |last4=Girgsdies |first4=Frank |last5=Seppelt |first5=Konrad |journal=Inorganic Chemistry |volume=49 |issue=9 |pages=4263–4267 |pmid=20380384}} A similar motif is adopted by titanium tetrafluoride.
Synthesis and reactions
The compound can be obtained by thermal decomposition of the sodium tetrafluorodioxomolybdate(VI) {{chem2|Na2[MoO2F4]}}, which in turn is obtained from sodium molybdate:
:{{chem2|Na2MoO4 + 4 HF -> Na2[MoO2F4] + 2 H2O}}
Heating sodium tetrafluorodioxomolybdate(VI) to 400 °C gives monomeric molybdenum difluoride dioxide, which polymerizes upon condensation:
:{{chem2|Na2[MoO2F4] -> 2 NaF + MoO2F2}}
The compound also arises by hydrolysis of molybdenum oxytetrafluoride:
:{{chem2|MoOF4 + H2O -> 2 HF + MoO2F2}}
The compound dissolves in dimethylformamide to give a adduct molybdenum difluoride dioxide bis(dimethylformamide):{{cite journal |doi=10.1039/C2CS35263J |title=Medium and high oxidation state metal/Non-metal fluoride and oxide–fluoride complexes with neutral donor ligands |year=2013 |last1=Benjamin |first1=Sophie L. |last2=Levason |first2=William |last3=Reid |first3=Gillian |journal=Chem. Soc. Rev. |volume=42 |issue=4 |pages=1460–1499 |pmid=23014811}}
:{{chem2|MoO2F2 + 2 HC(\dO)\sN(CH3)2 -> MoO2F2(HC(\dO)\sN(CH3)2)2}}
Further reading
- {{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}}
- {{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}}