|Molar mass||192.75 g/mol|
|Appearance||bright red liquid, moisture sensitive|
|Density||1.816 g/cm3, liquid|
|Melting point||−28 °C (−18 °F; 245 K)|
|Boiling point||154 °C (309 °F; 427 K)|
|Solubility in other solvents||chlorocarbons, hydrochloric acid|
|Vapor pressure||7.9 Pa|
|Dipole moment||0 D|
|Main hazards||oxidizer; hydrolyzes to release HCl|
|EU Index||Not listed|
|vanadium tetrafluoride, vanadium disulfide, vanadium tetrabromide|
|titanium tetrachloride, chromium tetrachloride, niobium tetrachloride, tantalum tetrachloride|
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
Synthesis, bonding, basic properties
With one more valence electron than diamagnetic TiCl4, VCl4 is a paramagnetic liquid. It is one of only a few paramagnetic compounds that is liquid at room temperature.
VCl4 is prepared by chlorination of vanadium metal. VCl5 does not form; Cl2 lacks the oxidizing power to attack VCl4. In contrast, the heavier analogues NbCl5 and TaCl5 are stable and not particularly oxidizing. Of course, VF5 does exist, reflecting the increased oxidizing power of F2 vs Cl2. Indicative of its oxidizing power, VCl4 releases Cl2 at its boiling point (standard pressure) to afford vanadium(III) chloride.
- 2 VCl4 + 8 HBr → 2 VBr3 + 8 HCl + Br2
It is the precursor to vanadocene dichloride.
VCl4 is a catalyst for the polymerization of alkenes, especially those useful in the rubber industry. The underlying technology is related to Ziegler-Natta catalysis, which involves the intermediacy of vanadium alkyls.
- 2 C6H5OH + 2 VCl4 → HOC6H4–C6H4OH + 2 VCl3 + 2 HCl
This reaction highlights the oxidizing ability of VCl4, consistent with it being resistant to further oxidation by Cl2.
VCl4 is a volatile, aggressive oxidant that readily hydrolyzes to release HCl.
- Calderazzo, F.; Maichle-Mossmer, C.; Pampaloni, G. and Strähle, J. (1993). "Low-temperature Syntheses of Vanadium(III) and Molybdenum(IV) Bromides by Halide Exchange". Dalton Transactions: 655–8. doi:10.1039/DT9930000655.
- M. K. O’Brien, B. Vanasse, “Vanadium(IV) Chloride” in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York.