Cyclopentadienylvanadium tetracarbonyl is the organovanadium compound with the formula (C<sub>5</sub>H<sub>5</sub>)V(CO)<sub>4</sub>. An orange, diamagnetic solid, it is the principal cyclopentadienyl carbonyl of vanadium. It can be prepared by heating a solution of vanadocene under high pressure of carbon monoxide. As confirmed by X-ray crystallography, the coordination sphere of vanadium consists of ÷<sup>5</sup>-cyclopentadienyl and four carbonyl ligands. The molecule is a four-legged piano stool complex. The compound is soluble in common organic solvents. The compound has no commercial applications.
Reduction of cyclopentadienylvanadium tetracarbonylwith sodium amalgam gives the tricarbonyl dianion:
Protonation of this salt gives Cp<sub>2</sub>V<sub>2</sub>(CO)<sub>5</sub>.
Heating a mixture of cycloheptatriene and cyclopentadienylvanadium tetracarbonyl gives (cycloheptatrienyl)(cyclopentadienyl)vanadium ("trovacene").