Zirconium(III) chloride

Zirconium(III) Chloride
IUPAC name

Zirconium trichloride
Identifiers
CAS number 10241-03-9
Properties
Molecular formula ZrCl3
Molar mass 197.583 g/mol
Appearance blue-black crystals
Density 2.20- 3.05 g/cm3
Boiling point

330 °C
Solubility in water hydrolysis
Solubility soluble in water
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Zirconium(III) chloride is a the inorganic compound with formula ZrCl3. It is a blue-black solid that is highly sensitive to air.

Preparation

The material was first claimed by Ruff and Wallstein who reduced zirconium tetrachloride with aluminium to give impure samples.[1] Subsequently, the problem with aluminium contamination was solved when it was prepared by reduction using zirconium metal:[2]

Zr + 3 ZrCl4 → 4 ZrCl3

When aluminium is used as the reducing agent with zirconium tetrachloride, a series of choloroaluminates are formed, for example [Zr(AlCl4)2(AlCl4)2] and Zr(AlCl4)3.[3]

Since the trihalides, such as zirconium trichloride, are comparatively nonvolatile, contamination can be avoided by using a gaseous reductant. For example, zirconium trichloride can be prepared by reduction of zirconium tetrachloride with hydrogen.[4]

ZrCl4 + 1/2H2 → ZrCl3 + HCl

Structure

ZrCl3 adopts a cubic close packed (ccp) structure in which Zr fills one third of the octahedral holes, similar to AlF3 and AlBr3. The Zr-Cl distance is 2.64 Å. Alternating strong and weak bonding between Zr centres is evidences by Zr-Zr distances of 303 and 342 pm.[5] The magnetic susceptibility of zirconium trichloride suggests metal-metal interactions of the unpaired electron on each Zr(III) center. The magnetic moment of ZrCl3 (0.4 BM) indicates considerable overlap of metal orbitals.[6]

References

  1. ^ Ruff, Otto; Wallstein, Richard (1923). "Reduktion anorganischer Halogenide III.1) Die Reduktion des Zirkontetrachlorids". Zeitschrift für anorganische und allgemeine Chemie 128: 96. doi:10.1002/zaac.19231280110. 
  2. ^ Hoffman, David M.; Lee, Samkeun (1992). "Synthesis of pyridine complexes of zirconium(III) chloride and the apparent oxidation to zirconium(IV) by a nitrile". Inorganic Chemistry 31 (13): 2675. doi:10.1021/ic00039a002. 
  3. ^ Larsen, E. M.; Moyer, James W.; Gil-Arnao, Francisco.; Camp, Michael J. (1974). "Synthesis of crystalline zirconium trihalides by reduction of tetrahalides in molten aluminum halides. Nonreduction of hafnium". Inorganic Chemistry 13 (3): 574. doi:10.1021/ic50133a015. 
  4. ^ Newnham, I. E.; Watts, J. A. (1960). "The Preparation of the Anhydrous Zirconium Trihalides". Journal of the American Chemical Society 82 (9): 2113. doi:10.1021/ja01494a006. 
  5. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Oxford: Butterworth-Heinemann. ISBN 0080379419. 
  6. ^ Wells, A.F. Structural Inorganic Chemistry. Oxford Science Publications, 1975, 5th ed, 417-420.