Vanadium trichloride oxide
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||173.300 g mol−1|
|Density||1.826 g mL−1|
|Melting point||−76.5 °C (−105.7 °F; 196.7 K)|
|Boiling point||126.7 °C (260.1 °F; 399.8 K)|
|Vapor pressure||1.84 kPa (at 20 °C)|
|GHS Signal word||Danger|
|P280, P301+310, P305+351+338, P310|
|NFPA 704 (fire diamond)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|140 mg kg−1 (oral, rat)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Vanadium oxytrichloride is the inorganic compound with the formula VOCl3. This yellow distillable liquid hydrolyzes readily in air. It is an oxidizing agent. It is used as a reagent in organic synthesis. Samples often appear red or orange owing to an impurity of vanadium tetrachloride.
VOCl3 is a vanadium compound with vanadium in the +5 oxidation state and as such is diamagnetic. It is tetrahedral with O-V-Cl bond angles of 111° and Cl-V-Cl bond angles of 108°. The V-O and V-Cl bond lengths are 157 and 214 pm, respectively. VOCl3 is highly reactive toward water and evolves HCl upon standing. It is soluble in nonpolar solvents such as benzene, CH2Cl2, and hexane. In some aspects, the chemical properties of VOCl3 and POCl3 are similar. One distinction is that VOCl3 is a strong oxidizing agent, whereas the phosphorus compound is not.
- 3 Cl2 + V2O5 → 2 VOCl3 + 1.5 O2
Heating an intimate (well-blended with tiny particles) mixture of V2O5 and carbon at 200–400 °C gives VOCl3. In this case the carbon serves as a deoxygenation agent akin to its use in the Kroll process for the manufacturing of TiCl4 from TiO2.
Vanadium(III) oxide can also be used as a precursor:
- 3 Cl2 + V2O3 → 2 VOCl3 + 0.5 O2
- V2O5 + 3 SOCl2 → 2 VOCl3 + 3 SO2
Hydrolysis and alcoholysis
- 2 VOCl3 + 3 H2O → V2O5 + 6 HCl
- VOCl3 + 3 HOCH(CH3)2 → VO(OCH(CH3)2)3 + 3 HCl
Interconversions to other V-O-Cl compounds
VOCl3 is also used in the synthesis of vanadium oxydichloride.
- V2O5 + 3 VCl3 + VOCl3 → 6 VOCl2
- VOCl3 + Cl2O → VO2Cl + 2 Cl2
At >180 °C, VO2Cl decomposes to V2O5 and VOCl3. Similarly, VOCl2 also decomposes to give VOCl3, together with VOCl.
VOCl3 is strongly Lewis acidic, as demonstrated by its tendency to form adducts with various bases such as acetonitrile and amines. In forming the adducts, vanadium changes from four-coordinate tetrahedral geometry to six-coordinate octahedral geometry:
- VOCl3 + 2 H2NEt → VOCl3(H2NEt)2
VOCl3 in alkene polymerization
VOCl3 is used as a catalyst or precatalytst in production of ethylene-propylene rubbers (EPDM).
- M. O'Brien, B. Vanasse (2001). Encyclopedia of Reagents for Organic Synthesis.
- F. E. Brown, F. A. Griffitts (1939). "Hypovanadous Oxide and Vanadium Oxytrichloride". Inorg. Synth. I: 106–108. doi:10.1002/9780470132326.ch38.CS1 maint: uses authors parameter (link)
- A. Earnshaw, N. Greenwood (1997). The Chemistry of the Elements - Second Edition. pp. 513–514.
- Holleman, Arnold Frederik; Wiberg, Egon; Wiberg, Nils (2001). Inorganic Chemistry. Academic Press. ISBN 9780123526519.
- G. Brauer "Vanadium oxytrichloride" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1264.
- Oppermann, H. (1967). "Untersuchungen an Vanadinoxidchloriden und Vanadinchloriden. I. Gleichgewichte mit VOCl3, VO2Cl und VOCl2". Zeitschrift für anorganische und allgemeine Chemie. 351 (3–4): 113–126. doi:10.1002/zaac.19673510302.