 | |
| Names | |
|---|---|
| IUPAC name Vanadocene | |
| Systematic IUPAC name Bis(η5-cyclopentadienyl)vanadium | |
| Identifiers | |
3D model (JSmol) | |
| ECHA InfoCard | 100.149.756 |
| UNII | |
| |
| Properties | |
| V(C5H5)2 | |
| Molar mass | 181.128 g/mol |
| Appearance | Violet Crystal |
| Melting point | 167 °C (333 °F; 440 K) |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Vanadocene, bis(η5-cyclopentadienyl) vanadium, is theorganometallic 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 extensively studied.
V(C5H5)2 is ametallocene, a class oforganometallic compounds that typically have a metal ion sandwiched between two cyclopentadienyl rings. In the solid state, the molecule has D5dsymmetry. The vanadium(II) center resides equidistant between the center of the twocyclopentadienyl rings at a crystallographic center of inversion. The average V-C bond distance is 226 pm.[1] The Cp rings of vanadocene are dynamically disordered at temperatures above 170 K and are only fully ordered at 108 K.
Vanadocene was first prepared in 1954 by Birmingham, Fischer, andWilkinson via a reduction ofvanadocene dichloride with aluminum hydride, after which vanadocene was sublimed in vacuum at 100 ˚C.[2] A modern synthesis of vanadocene that allows production in higher quantities requires treating [V2Cl3(THF)6]2[Zn2Cl6] withcyclopentadienylsodium.[3]
Vanadocene is a reactive molecule. As it only has 15 valence electrons available, it readily reacts with many ligands. With alkynes, for example, it reacts to yield the corresponding vanadium-cyclopropene complexes.[4]
One reaction involves carbon monoxide, leading to an ionic vanadocene derivative when performed in inert atmosphere:
Vanadocene is readily oxidized to the monocation when treated with aferrocenium salt in toluene.[5]
These monocations are extremelyair-sensitive and have a redox potential of -1.10 V.[5]
Vanadocene reacts with high pressures of carbon monoxide to giveCpV(CO)4.[6]
