Vanadium tetrafluoride

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.^[5] It decomposes before melting.

Vanadium(IV) fluoride

3D model of vanadium(IV) fluoride 3D model of vanadium(IV) fluoride
Names
IUPAC name vanadium tetrafluoride
Identifiers
CAS Number	10049-16-8
3D model (JSmol)	Interactive image
ChemSpider	11226730 Y
ECHA InfoCard	100.030.143
EC Number	233-171-7
PubChem CID	44717705
UNII	M372NC1A3B Y
UN number	UN2923
CompTox Dashboard (EPA)	DTXSID50894991
InChI InChI=1S/4FH.V/h4*1H;/q;;;;+4/p-4 Y Key: JTWLHYPUICYOLE-UHFFFAOYSA-J Y InChI=1/4FH.V/h4*1H;/q;;;;+4/p-4 Key: JTWLHYPUICYOLE-XBHQNQODAC
SMILES [V+4].[F-].[F-].[F-].[F-]
Properties
Chemical formula	F4V
Molar mass	126.9351 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 (S⦵298)	126 J/mol·K[3]
Std enthalpy of formation (ΔfH⦵298)	−1412 kJ/mol[3]
Gibbs free energy (ΔfG⦵)	−1312 kJ/mol[3]
Hazards
Occupational safety and health (OHS/OSH):
Eye hazards	Causes serious damage
Skin hazards	Causes burns
GHS labelling:[4]
Pictograms
Signal word	Danger
Hazard statements	H300, H314, H330
Precautionary statements	P260, P301+P310, P303+P361+P353, P304+P340, P305+P351+P338, P320, P330, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Preparation and reactions

VF₄ can be prepared by treating VCl₄ with HF:

VCl₄ + 4 HF → VF₄ + 4 HCl

It was first prepared in this way.^[6]

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

2 VF₄ → VF₃ + VF₅

Structure

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.^[7]

• 
    V⁴⁺;   F⁻