Molybdenum tetrachloride

Molybdenum tetrachloride
IUPAC name

Molybdenum tetrachloride
Other names

Molybdenum(IV) chloride
Properties
Molecular formula Cl4Mo
Appearance black solid
Melting point

552°C
Solubility in water Decomposes
Hazards
NFPA 704
0
3
1
Flash point Non flammable
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Molybdenum tetrachloride is the inorganic compound with the empirical formula MoCl4. The material exists as two polymorphs, a polymeric ("α") and a hexameric ("β") structures, although neither form is soluble in any solvent without degradation. In each polymorph, the Mo center is octahedral with two terminal chloride ligands and four doubly bridging ligands.[1]

It can be prepared from by dechlorination of molybdenum pentachloride using tetrachloroethene:[2]

2 MoCl5 + C2Cl4 → 2 MoCl4 + C2Cl6

The acetonitrile adduct, which is a versatile intermediate, can be prepared directly from the pentachloride:[3]

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

References

  1. ^ Ulrich Müller "Hexameric Molybdenum Tetrachloride" Angewandte Chemie International Edition in English 1981, Volume 20, Pages 692 - 693. doi: 10.1002/anie.198106921
  2. ^ E. L. Mccann III, T. M. Brown "Molybpenum(IV) Chloride" Inorganic Syntheses 1970, volume 12, pages 181-186. doi:10.1002/9780470132432.ch31
  3. ^ Jonathan R. Dilworth, Raymond L. Richards "The Synthesis of Molybdenum and Tungsten Dinitrogen Complexes" Inorganic Syntheses 1990, volume 28, pages 33-43. doi: 10.1002/9780470132593