Cyclopentadienylvanadium tetracarbonyl is the

organovanadium compound Organovanadium chemistry is the chemistry of organometallic compounds containing a carbon (C) to vanadium (V) chemical bond. Organovanadium compounds find only minor use as reagents in organic synthesis but are significant for polymer chemistry as c ...

with the formula (C₅H₅)V(CO)₄. An orange, diamagnetic solid, it is the principal cyclopentadienyl carbonyl of vanadium. It can be prepared by heating a solution of

vanadocene Vanadocene, bis(η5-cyclopentadienyl) vanadium, is the organometallic compound with the formula V(C5H5)2, commonly abbreviated Cp2V. It is a violet crystalline, paramagnetic solid. Vanadocene has relatively limited practical use, but it has been ex ...

under high pressure of

carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...

. As confirmed by

X-ray crystallography X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles ...

, the coordination sphere of vanadium consists of η⁵-

cyclopentadienyl Cyclopentadienyl can refer to *Cyclopentadienyl anion, or cyclopentadienide, **Cyclopentadienyl ligand *Cyclopentadienyl radical, • *Cyclopentadienyl cation, See also *Pentadienyl In organic chemistry, pentadienyl refers to the organic radic ...

and four

carbonyl ligand Metal carbonyls are coordination complexes of transition metals with carbon monoxide ligands. Metal carbonyls are useful in organic synthesis and as catalysts or catalyst precursors in homogeneous catalysis, such as hydroformylation and Reppe ch ...

s. The molecule is a four-legged

piano stool complex Half sandwich compounds, also known as piano stool complexes, are organometallic complexes that feature a cyclic polyhapto ligand bound to an MLn center, where L is a unidentate ligand. Thousands of such complexes are known. Well-known examples in ...

. The compound is soluble in common organic solvents. The compound has no commercial applications.

Reactions

Reduction with sodium amalgam gives the dianion of the tricarbonyl: :CpV(CO)₄ + 2 Na → Na₂CpV(CO)₃ + CO Protonation of this salt gives Cp₂V₂(CO)₅. Heating a mixture of

cycloheptatriene Cycloheptatriene (CHT) is an organic compound with the formula C7H8. It is a closed ring of seven carbon atoms joined by three double bonds (as the name implies) and four single bonds. This colourless liquid has been of recurring theoretical inter ...

and cyclopentadienylvanadium tetracarbonyl gives (cycloheptatrienyl)(cyclopentadienyl)vanadium ("trovacene").{{cite journal , doi=10.1021/ja01528a063, title=π-Cylopentadienyl-π-Cycloheptatrienyl Vanadium, year=1959, last1=King, first1=R. B., last2=Stone, first2=F. G. A., journal=Journal of the American Chemical Society, volume=81, issue=19, pages=5263–5264

References

Cyclopentadienyl complexes Carbonyl complexes Organovanadium compounds Half sandwich compounds