Names | |
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IUPAC name
hexacarbonylvanadium(0)
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Identifiers | |
3D model (
JSmol)
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ChEBI | |
ECHA InfoCard | 100.039.928 |
PubChem
CID
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UNII | |
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Properties | |
C6O6V | |
Molar mass | 219.00 g/mol |
Appearance | blue-green crystals yellow solutions |
Density | 1.7 g/cm3 |
Melting point | decomposes |
Boiling point | sublimes at 50 °C (122 °F; 323 K) (15 mmHg) |
insoluble | |
Solubility in other solvents | 5 g/L
hexane; more soluble in dichloromethane |
Structure | |
orthorhombic | |
octahedral | |
0 D | |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards
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CO source |
Related compounds | |
Related compounds
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Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Vanadium hexacarbonyl is the inorganic compound with the formula V(CO)6. It is a blue-black volatile solid. This highly reactive species is noteworthy from theoretical perspectives as a rare isolable homoleptic metal carbonyl that is paramagnetic. Most species with the formula Mx(CO)y follow the 18-electron rule, whereas V(CO)6 has 17 valence electrons. [1]
Traditionally V(CO)6 is prepared in two-steps via the intermediacy of V(CO)−
6. In the first step, VCl3 is reduced with metallic
sodium under 200 atm CO at 160 °C. The solvent for this reduction is typically
diglyme, CH3OCH2CH2OCH2CH2OCH3. This tri
ether solubilizes sodium salts, akin to the behavior of a
crown ether:
The resulting anion is oxidized with acid: [2]
Vanadium hexacarbonyl is thermally unstable. Its primary reaction is reduction to the monoanion V(CO)−
6, salts of which are well studied. It is also susceptible to substitution by tertiary
phosphine ligands, often leading to
disproportionation.
V(CO)6 reacts with sources of the
cyclopentadienyl anion to give the orange
four-legged piano stool complex (C5H5)V(CO)4 (m.p. 136 °C). Like many charge-neutral organometallic compounds, this half-sandwich species is volatile. In the original preparation of this species, C5H5HgCl was employed as the source of C
5H−
5.
V(CO)6 adopts an
octahedral coordination geometry and is isostructural with
chromium hexacarbonyl, even though they have differing valence electron counts. High resolution X-ray crystallography indicates that the molecule is slightly distorted with two (axial) shorter V–C distances of 1.993(2) Å vs. four (equatorial) 2.005(2) Å. Even though V(−I) is a larger ion than V(0), the V–C distances in V(CO)−
6 are 0.07 Å shorter than in the neutral precursor.
[3]