Vanadium tetrafluoride

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Vanadium(IV) fluoride
3D model of vanadium(IV) fluoride 3D model of vanadium(IV) fluoride
Identifiers
CAS number 10049-16-8
PubChem 165641
ChemSpider 11226730 YesY
EC number 233-171-7
UN number UN2923
Jmol-3D images Image 1
Properties
Molecular formula F4V
Molar mass 126.94 g mol−1
Appearance Lime green powder, hygroscopic[1]
Odor Odorless
Density 3.15 g/cm3 (20 °C)[1]
2.975 g/cm3 (23 °C)[2]
Melting point 325 °C (617 °F; 598 K)
at 760 mmHg decomposes[1]
Boiling point Sublimes[1]
Solubility in water Very soluble[1]
Solubility Soluble in acetone, acetic acid
Very slightly soluble in SO2Cl2, alcohols, CHCl3[2]
Structure
Crystal structure Monoclinic, mP10
Space group P21/c, No. 14
Thermochemistry
Std molar
entropy
So298
126 J/mol·K[3]
Std enthalpy of
formation
ΔfHo298
−1412 kJ/mol[3]
Gibbs free energy ΔG −1312 kJ/mol[3]
Hazards
GHS pictograms The corrosion pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The skull-and-crossbones pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)[4]
GHS signal word Danger
GHS hazard statements H300, H330, H314, H318[4]
GHS precautionary statements P260, P301+310, P303+361+353, P304+340, P305+351+338, P320, P330, P405, P501[4]
EU classification Toxic T
R-phrases R23/24/25, R34
S-phrases S22, S26, S36/37/39, S45
Eye hazard Causes serious damage
Skin hazard Causes burns
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Vanadium(IV) fluoride (VF4) is an inorganic compound of vanadium and fluorine. It is paramagnetic yellow-brown solid that is very hygroscopic.[2] Unlike the corresponding vanadium tetrachloride, the tetrafluoride is not volatile because it adopts a polymeric structure. It decomposes before melting.

Preparation and reactions[edit]

VF4 can be prepared by treating VCl4 with HF:

VCl4 + 4 HF → VF4 + 4 HCl

It was first prepared in this way.[5]

It decomposes 325 °C, undergoing disproportionation to the tri- and pentafluorides:[2]

2 VF4 → VF3 + VF5

Structure[edit]

     V4+;      F

The structure of VF4 is related to that of SnF4. Each vanadium centre is octahedral, surrounded by six fluoride ligands. Four of the fluoride centers bridge to adjacent vanadium centres.[6]

References[edit]

  1. ^ a b c d e Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4200-9084-0. 
  2. ^ a b c d Kwasnik, W. (1963). Brauer, Georg, ed. Handbook of Preparative Inorganic Chemistry (UK ed.). London: Academic Press. pp. 252–253. 
  3. ^ a b c Anatolievich, Kiper Ruslan. "vanadium(IV) fluoride". http://chemister.ru. Retrieved 2014-06-25. 
  4. ^ a b c "Vanadium(IV) fluoride, 95%". http://www.alfa.com. Alfa Aesar. Retrieved 2014-06-25. 
  5. ^ Otto Ruff, Herbert Lickfett "Vanadinfluoride" Chemische Berichte 1911, vol. 44, pages 2539–2549. doi:10.1002/cber.19110440379
  6. ^ Becker S., Muller B. G. Vanadium Tetrafluoride, Angew. Chem. Intnl. Ed. Engl. 1990, vol. 29, page 406