Encyclopedia of Chemistry

Vanadocene dichloride, dichlorobis(η⁵-2,4-cyclopentadien-1-yl) vanadium, or dicyclopentadienyl vanadium dichloride is (η⁵-C₅H₅)₂VCl₂ (commonly abbreviated as Cp₂VCl₂). It is a close relative of titanocene dichloride but with one additional valence electron, hence Cp₂VCl₂ is paramagnetic. Vanadocene dichloride is a useful precursor to other (C₅H₅)₂V compounds.

Preparation

Cp₂VCl₂ was first prepared by Wilkinson and Birmingham via the reaction of NaC₅H₅ and VCl₄ in THF, followed by work up by extraction with chloroform and hydrogen chloride and recrystallization from toluene.^[1]

Structure

Like its Ti analogue, vanadocene dichloride is currently being investigated as a potential anticancer drug (currently in clinical trials). The mechanism by which it acts is not understood, but some conjecture that it might be due to its interactions with the protein transferrin.^[2]

References

1. ^ G. Wilkinson and J.G. Birmingham (1954). "Bis-cyclopentadienyl Compounds of Ti, Zr, V, Nb and Ta". Journal of the American Chemical Society 76 (17): 4281-4284. doi:10.1021/ja01646a008.
2. ^ Murthy M. S., Rao L. N., Kuo L. Y., Toney J. H., Marks T. J. (1988). "Antitumor and toxicologic properties of the organometallic anticancer agent vanadocene dichloride.". Inorg. Chimica Acta 152: 117-124.

Further reading

• T. Hirao, A. Ogawa, M. Asahara, Y. Muguruma, H. Sakurai (2005). "d,l-Selective Pinacol-Type Coupling Using Zinc, Chlorosilane, and Catalytic Amount of Cp₂VCl₂; dl-1,2-Dicyclohexylethanediol". Org. Synth. 81: 26.