Zirconium(IV) bromide

Zirconium(IV) bromide
Names
	Other names zirconium tetrabromide
Identifiers
CAS Number	13777-25-8 ;
3D model (JSmol)	Interactive image;
ChemSpider	75549 ;
ECHA InfoCard	100.034.002
EC Number	237-417-4;
PubChem CID	83727;
CompTox Dashboard (EPA)	DTXSID6065630 ;
	InChI InChI=1S/4BrH.Zr/h41H;/q;;;;+4/p-4 Key: LSWWNKUULMMMIL-UHFFFAOYSA-J ; InChI=1/4BrH.Zr/h41H;/q;;;;+4/p-4 Key: LSWWNKUULMMMIL-XBHQNQODAM;
	SMILES Br[Zr](Br)(Br)Br;
Properties
Chemical formula	ZrBr4
Molar mass	410.86 g/mol
Appearance	off-white powder
Density	4.201 g/cm3, solid
Melting point	450 °C (842 °F; 723 K)
Boiling point	sublimes
Solubility in water	reacts with water
Structure
Crystal structure	Cubic, cP40
Space group	P-43m, No. 205
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314
Precautionary statements	P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501
NFPA 704 (fire diamond)	3 0 2
Related compounds
Other anions	Zirconium(IV) fluoride; Zirconium(IV) chloride; Zirconium(IV) iodide
Other cations	Titanium tetrabromide; Hafnium tetrabromide
Related compounds	Zirconium(III) bromide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Zirconium(IV) bromide is the inorganic compound with the formula ZrBr₄. This colourless solid is the principal precursor to other Zr–Br compounds.

Preparation and properties

ZrBr₄ is prepared by the action of bromine on zirconium oxide via a carbothermic reaction:^[1]

ZrO₂ + 2 C + 2 Br₂ → ZrBr₄ + 2 CO

Like many related tetrahalides, it is purified by sublimation.

It can also be prepared by treatment of the borohydride complex with hydrogen bromide:^[2]

Zr(BH₄)₄ + 4 HBr → ZrBr₄ + 4 H₂ + 2 B₂H₆

Like related tetrabromides of Ti and Hf, ZrBr₄ hydrolyzes readily to give the oxybromide, with release of hydrogen bromide.

Structure

No single crystal X-ray study of ZrBr₄ has been described. Some reports suggest that it is isostructural with TiCl₄ and TiBr₄, featuring tetrahedral metal centers.^[3] Other studies indicate a polymeric structure.^[4] ZrCl₄ is polymeric in the solid state, featuring octahedral Zr centers.^[5]

References

^ R. C. Young, Hewitt G. Fletcher, "Anhydrous Zirconium Tetrabromide" Inorganic Syntheses, 1939, vol. 1, pp. 49–51. doi:10.1002/9780470132326.ch18
^ Calderazzo, Fausto; Pallavicini, Piersandro; Pampaloni, Guido (1990). "Arene derivatives of zirconium(II) and hafnium(II)". Journal of the Chemical Society, Dalton Transactions (6): 1813. doi:10.1039/DT9900001813.
^ Berdonosov, S. S.; Lapitskii, A. V. (1963). "Structure of Zr and Hf Tetrabromides". Vestnik Moskovskogo Universiteta, Seriya 2: Khimiya. 18: 42–4. (from abstract): The structure was assumed to be similar to that of SnI₄ ... was verified by comparing exptl. and calcd. line intensities, by using Cu K radiation for powder patterns. ... Based on the value of the radius of the I− ion, the lattice parameter and the theoretical sp. gravity of ZrI₄ and HfI₄ were calcd.
^ Carter, J. C.; Smith, J. A. S. (1974). "Nuclear quadrupole resonance in hafnium and zirconium tetrabromide". Journal of the Chemical Society, Chemical Communications (20): 835–6. doi:10.1039/c39740000835.
^ A. F. Wells (1984). Structural Inorganic Chemistry. Oxford: Clarendon Press. ISBN 0-19-855370-6.

[1] R. C. Young, Hewitt G. Fletcher, "Anhydrous Zirconium Tetrabromide" Inorganic Syntheses, 1939, vol. 1, pp. 49–51. doi:10.1002/9780470132326.ch18

[2] Calderazzo, Fausto; Pallavicini, Piersandro; Pampaloni, Guido (1990). "Arene derivatives of zirconium(II) and hafnium(II)". Journal of the Chemical Society, Dalton Transactions (6): 1813. doi:10.1039/DT9900001813.

[3] Berdonosov, S. S.; Lapitskii, A. V. (1963). "Structure of Zr and Hf Tetrabromides". Vestnik Moskovskogo Universiteta, Seriya 2: Khimiya. 18: 42–4. (from abstract): The structure was assumed to be similar to that of SnI₄ ... was verified by comparing exptl. and calcd. line intensities, by using Cu K radiation for powder patterns. ... Based on the value of the radius of the I− ion, the lattice parameter and the theoretical sp. gravity of ZrI₄ and HfI₄ were calcd.

[4] Carter, J. C.; Smith, J. A. S. (1974). "Nuclear quadrupole resonance in hafnium and zirconium tetrabromide". Journal of the Chemical Society, Chemical Communications (20): 835–6. doi:10.1039/c39740000835.

[5] A. F. Wells (1984). Structural Inorganic Chemistry. Oxford: Clarendon Press. ISBN 0-19-855370-6.

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