Molybdenum tetrachloride
Names | |
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IUPAC name
Molybdenum tetrachloride
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Other names
Molybdenum(IV) chloride
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Identifiers | |
3D model (
JSmol ) |
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ChemSpider | |
ECHA InfoCard
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100.033.039 |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
Cl4Mo | |
Molar mass | 237.752 g/mol |
Appearance | black solid |
Melting point | 552 °C (1,026 °F; 825 K) |
Decomposes | |
Hazards | |
NFPA 704 (fire diamond) | |
Flash point | Non flammable |
Related compounds | |
Related compounds
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Molybdenum(II) chloride Molybdenum(III) chloride Molybdenum(V) chloride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Molybdenum tetrachloride is the
polymorphs
, both being dark-colored paramagnetic solids. These compounds are mainly of interest as precursors to other molybdenum complexes.
Structure
The α polymorph is a polymer. The β polymorph is a hexamer. In both polymorph, the Mo center is octahedral with two terminal chloride ligands and four doubly bridging ligands.Lewis base.
Preparation
α-Molybdenum tetrachloride can be prepared from by dechlorination of
tetrachloroethene:[2]
- 2 MoCl5 + C2Cl4 → 2 MoCl4 + C2Cl6
Heating α-molybdenum tetrachloride in a sealed container in the presence of molybdenum pentachloride induces conversion to the β polymorph.[2]
Reactions
When heated in an open container, molybdenum tetrachloride evolves chlorine, giving
molybdenum trichloride;[2]
- 2 MoCl4 → 2 MoCl3 + Cl2
The
acetonitrile complex adduct can be prepared by reduction of the pentachloride with acetonitrile:[3][4]
- 2 MoCl5 + 5 CH3CN → 2 MoCl4(CH3CN)2 + ClCH2CN + HCl
The MeCN ligands can be exchanged with other ligands:
- MoCl4(CH3CN)2 + 2 THF→ MoCl4(THF)2 + 2 CH3CN
The pentachloride can be reduced to the
ether complex MoCl4(Et2O)2 using tin powder. It is a beige, paramagnetic solid.[5]
References
- .
- ^ ISBN 9780470132432.
- ISBN 9781118744994.
- ISBN 9780470132593.
- ISBN 9781118744994.