Vanadocene
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IUPAC name
Bis(cyclopentadienyl)vanadium
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Other names
Vanadocene
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Identifiers | |
3D model (
JSmol ) |
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ECHA InfoCard
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100.149.756 |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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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 their standard state (at 25 °C [77 °F], 100 kPa).
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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 extensively studied.
Structure and bonding
V(C5H5)2 is a
organometallic compounds that typically have a metal ion sandwiched between two cyclopentadienyl rings. In the solid state, the molecule has D5d symmetry. The vanadium(II) center resides equidistant between the center of the two cyclopentadienyl 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.
Preparation
Vanadocene was first prepared in 1954 by Birmingham, Fischer, and
cyclopentadienylsodium.[3]
- 2 [V2Cl3(THF)6]2[Zn2Cl6] + 8 NaCp + THF → 4 Cp2V
Properties
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:
- Cp2V + V(CO)6 → [Cp2V(CO)2][V(CO)6]
Vanadocene is readily oxidized to the monocation when treated with a
ferrocenium salt in toluene.[5]
- VCp2 + [FeCp2]BR4 → [VCp2]BR4 + FeCp2 (R = Ph or 4-C6H4F)
These monocations are extremely
air-sensitive and have a redox potential of -1.10 V.[5]
Vanadocene reacts with high pressures of carbon monoxide to give CpV(CO)4.[6]
References
- S2CID 93048446.
- S2CID 44523847.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - ^ Lorber, C. "Vanadium Organometallics." Chapter 5.01. Comprehensive Organometallic Chemistry III. Elsevier, 2007. 1-60.
- ^ Jordan, Markus (2009). Azine in der Koordinationssphäre von Vanadocenderivaten unterschiedlicher Oxidationsstufen (PhD thesis). Universität Oldenburg.
- ^ doi:10.1021/om9809320.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - )