- Zirconium(IV) chloride
Chembox new
ImageFile = Zirconium-tetrachloride-3D-balls-A.png
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Name = Zirconium(IV) chloride
OtherNames = Zirconium tetrachloride
Section1 = Chembox Identifiers
CASNo = 10026-11-6
EINECS = 233-058-2
Section2 = Chembox Properties
Formula = ZrCl4
MolarMass = 233.04 g/mol
Solvent = other solvents
SolubleOther = hydrolysis inwater
soluble inalcohol
MeltingPt =
BoilingPt = 331°C "subl."
Section4 = Chembox Thermochemistry
DeltaHf = -980.52 kJ/mol
Entropy = 181.41 J.K–1.mol–1
Cp = 125.38 J.K–1.mol–1Zirconium(IV) chloride, also known as zirconium tetrachloride, is the
inorganic compound with the formula ZrCl4. This white high-melting solid hydrolyzes rapidly in humid air. It is a keyreagent in the chemistry ofzirconium .tructure
Unlike TiCl4, ZrCl4 adopts a polymeric structure wherein each Zr is octahedrally coordinated. This difference in structures, polymeric vs. molecular, is responsible for the striking difference in their properties - one being distillable, the other being a high melting solid. In the solid state, ZrCl4 adopts a tape-like linear polymeric structure--the same structure adopted by HfCl4. This polymer degrades readily upon treatment with
Lewis base s, which cleave the Zr-Cl-Zr linkages. [N. N. Greenwood & A. Earnshaw, "Chemistry of the Elements" (2nd ed.), Butterworth-Heinemann, Oxford, 1997.]Kroll process
ZrCl4 is an intermediate in the conversion of zirconium minerals to metallic
zirconium by theKroll process . In nature, zirconium minerals invaribly exists as oxides (reflected also by the tendency of all zirconium chlorides to hydrolyze). For their conversion to bulk metal, these refractory oxides are first converted to the tetrachloride, which can be distilled at high temperatures. This conversion entails treatment of the oxide with carbon as the oxide "getter" and chlorine.:ZrO2 + 2 C + 2 Cl2 → ZrCl4 + 2 COChemical reactions
ZrCl4 is the principal starting compound for the synthesis of many organometallic complexes of zironcium. [New Aspects of Zirconium Containing Organic Compounds. Topics in Organometallic Chemistry, 10 Edited by Ilan Marek (Technion-Israel Institute of Technology, Haifa). Springer: Berlin, Heidelberg, New York. 2005. x + 176 pp. ISBN 3-540-22221-9.] Because of its polymeric structure, ZrCl4 it is usually converted to a molecular complex before use. It forms a 1:2 complex with
tetrahydrofuran : CAS [21959-01-3] , mp 175-177 °C. [cite journal | author = L. E. Manxzer, Joe Deaton, Paul Sharp, R. R. Schrock | title = Tetrahydrofuran Complexes of Selected Early Transition Metals | journal =Inorganic Syntheses | year = 1982 | volume = 21 | pages = 135–40 | doi = 10.1002/9780470132524.ch31] NaC5H5 reacts with ZrCl4(THF)2 to give zirconocene dichloride, ZrCl2(C5H5)2, a versatile organozirconium complex. [cite journal | author = G. Wilkinson and J.G. Birmingham | year = 1954 | title = Bis-cyclopentadienyl Compounds of Ti, Zr, V, Nb and Ta | journal =J. Am. Chem. Soc. | volume = 76 | issue = 17 | pages = 4281–4284 | doi = 10.1021/ja01646a008] One of the most curious properties of ZrCl4 is its high solubility in the presence of methylated benzenes, such asdurene . This solubilization arises through the formation of π-complexes. [cite journal | author = Musso, F.; Solari, E.; Floriani, C.; Schenk, K. | title = Hydrocarbon Activation with Metal Halides: Zirconium Tetrachloride Catalyzing the Jacobsen Reaction and Assisting the Trimerization of Alkynes via the Formation of η6-Arene-Zirconium(IV) Complexes | journal =Organometallics | year = 1997 | volume = 16 | pages = 4889–4895 | doi = 10.1021/om970438g]Uses
In organic synthesis zirconium tetrachloride is used as a weak
Lewis acid for theFriedel-Crafts reaction , theDiels-Alder reaction and intramolecular cyclisation reactions. [cite journal | author= Bora U. | title= Zirconium Tetrachloride | journal=Synlett | year= 2003 | pages= 1073–1074 |doi=10.1055/s-2003-39323] It is also used to make water-repellenttextile s.References
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