Zirconium(III) chloride

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

Zirconium(III) chloride

3D model of zirconium(III) chloride
Names
IUPAC name Zirconium trichloride
Identifiers
CAS Number	10241-03-9 Y
3D model (JSmol)	Interactive image
ChemSpider	127679 N
PubChem CID	144719
CompTox Dashboard (EPA)	DTXSID101029428
InChI InChI=1S/3ClH.Zr/h3*1H;/q;;;+3/p-3 N Key: PFXYQVJESZAMSV-UHFFFAOYSA-K N
SMILES Cl[Zr](Cl)Cl
Properties
Chemical formula	Cl3Zr
Molar mass	197.57 g·mol−1
Appearance	Blue-black crystals
Density	3.05 g/cm3[1]
Melting point	627 °C (1,161 °F; 900 K) at 760 mmHg[1]
Solubility in water	Reacts[1]
Solubility	Soluble in benzene, CS2
Structure
Crystal structure	Hexagonal, hP6[2]
Space group	P63/mcm, No. 193[2]
Point group	6/m 2/m 2/m[2]
Lattice constant	a = 6.36 Å, c = 6.14 Å[2] α = 90°, β = 90°, γ = 120°
Thermochemistry
Heat capacity (C)	96.21 J/mol·K[3]
Std molar entropy (S⦵298)	145.79 J/mol·K[3]
Std enthalpy of formation (ΔfH⦵298)	−714.21 kJ/mol[3]
Related compounds
Other anions	Zirconium(III) bromide Zirconium(III) iodide
Other cations	Titanium(III) chloride Hafnium(III) chloride
Related compounds	Zirconium(IV) chloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Preparation

The material was first claimed by Ruff and Wallstein who reduced zirconium tetrachloride with aluminium to give impure samples.^[4] Subsequently, the problem with aluminium contamination was solved when it was prepared by reduction using zirconium metal:^[5]

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.^[6]

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.^[7]

ZrCl₄ + ½ H₂ → ZrCl₃ + HCl

Structure

Some zirconium halides (ZrCl₃, ZrBr₃, and ZrI₃) have structures similar to HfI₃. They also have similar space group (P6₃/mcm) and hexagonal structure with 2 molecules in the cell.^[2] 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.^[8]