Cyclopentadienylvanadium tetracarbonyl explained

Cyclopentadienylvanadium tetracarbonyl is the organovanadium compound 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 under high pressure of carbon monoxide.^[1] As confirmed by X-ray crystallography, the coordination sphere of vanadium consists of η⁵-cyclopentadienyl and four carbonyl ligands. The molecule is a four-legged piano stool complex.^[2] The compound is soluble in common organic solvents.^[3] 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 + COProtonation of this salt gives Cp₂V₂(CO)₅.^[4]

Heating a mixture of cycloheptatriene and cyclopentadienylvanadium tetracarbonyl gives (cycloheptatrienyl)(cyclopentadienyl)vanadium ("trovacene").^[5]

References

1. 10.1002/9780470132388.ch30. Cyclopentadienyl Metal Carbonyls and Some Derivatives. Inorganic Syntheses. 1963. King. R. B.. Stone. F. G. A.. 7. 99–104.
2. 10.1016/S0022-328X(00)83671-2. The Crystal and Molecular Structure of π-Cyclopentadienylvanadium Tetracarbonyl. 1967. Wilford. J.B.. Whitla. A.. Powell. H.M.. Journal of Organometallic Chemistry. 8. 3. 495–502.
3. Book: King, R.B. . . Cyclopentadienyl Metal Carbonyls and Some Derivatives . . 7 . 10.1002/9780470132388.ch31 . 1963 . 99–115. 9780470132388 .
4. 10.1002/cber.19701031133. Über Aromatenkomplexe von Metallen, CXIV. Darstellung und Reaktionen von Dicyclopentadienyl-divanadin-pentacarbonyl, (C 5 H 5) 2 V 2 (CO) 5. 1970. Fischer. Ernst Otto. Schneider. Robert J. J.. Chemische Berichte. 103. 11. 3684–3695.
5. 10.1021/ja01528a063. π-Cylopentadienyl-π-Cycloheptatrienyl Vanadium. 1959. King. R. B.. Stone. F. G. A.. Journal of the American Chemical Society. 81. 19. 5263–5264.