![]() | |
![]() | |
![]() | |
Names | |
---|---|
IUPAC names Zirconium tetrachloride Zirconium(IV) chloride | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.030.041 |
EC Number |
|
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
| |
| |
Properties | |
ZrCl4 | |
Molar mass | 233.04 g/mol |
Appearance | white crystals |
Density | 2.80 g/cm3 |
Melting point | 437 °C (819 °F; 710 K) (triple point) |
Boiling point | 331 °C (628 °F; 604 K) (sublimes) |
hydrolysis | |
Solubility | concentrated HCl (with reaction) |
Structure | |
Monoclinic, mP10 | |
P12/c1, No. 13 | |
Thermochemistry | |
Heat capacity (C) | 125.38 J K−1 mol−1 |
Std molar entropy (S⦵298) | 181.41 J K−1 mol−1 |
Std enthalpy of formation (ΔfH⦵298) | −980.52 kJ/mol |
Hazards | |
GHS labelling: [1] | |
![]() ![]() ![]() | |
Danger | |
H290, H302, H312, H314, H317, H332, H334 | |
P234, P260, P261, P264, P270, P271, P272, P280, P285, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P312, P304+P340, P304+P341, P305+P351+P338, P310, P312, P321, P322, P330, P333+P313, P342+P311, P363, P390, P404, P405, P501 | |
NFPA 704 (fire diamond) | |
Flash point | Non-flammable |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 1488-1500 mg/kg (oral, rat) 655 mg/kg (mouse, oral) [2] |
Safety data sheet (SDS) | MSDS |
Related compounds | |
Other anions | Zirconium(IV) fluoride Zirconium(IV) bromide Zirconium(IV) iodide |
Other cations | Titanium tetrachloride Hafnium tetrachloride |
Related compounds | Zirconium(II) chloride, Zirconium(III) chloride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Zirconium(IV) chloride, also known as zirconium tetrachloride, ( Zr Cl 4) is an inorganic compound frequently used as a precursor to other compounds of zirconium. This white high-melting solid hydrolyzes rapidly in humid air.
Unlike molecular TiCl4, solid ZrCl4 adopts a polymeric structure wherein each Zr is octahedrally coordinated. This difference in structures is responsible for the disparity in their properties: TiCl
4 is distillable, but ZrCl
4 is a 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 bases, which cleave the Zr-Cl-Zr linkages. [4]
This conversion entails treatment of zirconium oxide with carbon in the presence of chlorine at high temperature:
A laboratory scale process uses carbon tetrachloride in place of carbon and chlorine: [5]
ZrCl4 is an intermediate in the conversion of zirconium minerals to metallic zirconium by the Kroll process. In nature, zirconium minerals usually exist 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. The purified ZrCl4 can be reduced with Zr metal to produce zirconium(III) chloride.
ZrCl4 is the most common precursor for chemical vapor deposition of zirconium dioxide and zirconium diboride. [6]
In organic synthesis zirconium tetrachloride is used as a weak Lewis acid for the Friedel-Crafts reaction, the Diels-Alder reaction and intramolecular cyclisation reactions. [7] It is also used to make water-repellent treatment of textiles and other fibrous materials.
Hydrolysis of ZrCl4 gives the hydrated hydroxy chloride cluster called zirconyl chloride. This reaction is rapid and virtually irreversible, consistent with the high oxophilicity of zirconium(IV). For this reason, manipulations of ZrCl4 typically require air-free techniques.
ZrCl4 is the principal starting compound for the synthesis of many organometallic complexes of zirconium. [8] Because of its polymeric structure, ZrCl4 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. [9] Sodium cyclopentadienide (NaC5H5) reacts with ZrCl4(THF)2 to give zirconocene dichloride, ZrCl2(C5H5)2, a versatile organozirconium complex. [10] One of the most curious properties of ZrCl4 is its high solubility in the presence of methylated benzenes, such as durene. This solubilization arises through the formation of π-complexes. [11]
The log (base 10) of the vapor pressure of zirconium tetrachloride (from 480 to 689 K) is given by the equation: log10(P) = −5400/T + 11.766, where the pressure is measured in torrs and temperature in kelvins. The log (base 10) of the vapor pressure of solid zirconium tetrachloride (from 710 to 741 K) is given by the equation log10(P) = −3427/T + 9.088. The pressure at the melting point is 14,500 torrs. [12]
Zirconium is a chemical element; it has symbol Zr and atomic number 40. First isolated in pure form in 1824, the name zirconium is derived from the name of the mineral zircon, the most important source of zirconium. The word is related to Persian zargun. It is a lustrous, grey-white, strong transition metal that closely resembles hafnium and, to a lesser extent, titanium.
A Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, is a catalyst used in the synthesis of polymers of 1-alkenes (alpha-olefins). Two broad classes of Ziegler–Natta catalysts are employed, distinguished by their solubility:
Titanium tetrachloride is the inorganic compound with the formula TiCl4. It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. TiCl4 is a volatile liquid. Upon contact with humid air, it forms thick clouds of titanium dioxide and hydrochloric acid, a reaction that was formerly exploited for use in smoke machines. It is sometimes referred to as "tickle" or "tickle 4", as a phonetic representation of the symbols of its molecular formula.
Hafnium(IV) chloride is the inorganic compound with the formula HfCl4. This colourless solid is the precursor to most hafnium organometallic compounds. It has a variety of highly specialized applications, mainly in materials science and as a catalyst.
Titanocene dichloride is the organotitanium compound with the formula (η5-C5H5)2TiCl2, commonly abbreviated as Cp2TiCl2. This metallocene is a common reagent in organometallic and organic synthesis. It exists as a bright red solid that slowly hydrolyzes in air. It shows antitumour activity and was the first non-platinum complex to undergo clinical trials as a chemotherapy drug.
Zirconium(IV) bromide is the inorganic compound with the formula ZrBr4. This colourless solid is the principal precursor to other Zr–Br compounds.
Schwartz's reagent is the common name for the organozirconium compound with the formula (C5H5)2ZrHCl, sometimes called zirconocene hydrochloride or zirconocene chloride hydride, and is named after Jeffrey Schwartz, a chemistry professor at Princeton University. This metallocene is used in organic synthesis for various transformations of alkenes and alkynes.
Organotitanium chemistry is the science of organotitanium compounds describing their physical properties, synthesis, and reactions. Organotitanium compounds in organometallic chemistry contain carbon-titanium chemical bonds. They are reagents in organic chemistry and are involved in major industrial processes.
Niobocene dichloride is the organometallic compound with the formula (C5H5)2NbCl2, abbreviated Cp2NbCl2. This paramagnetic brown solid is a starting reagent for the synthesis of other organoniobium compounds. The compound adopts a pseudotetrahedral structure with two cyclopentadienyl and two chloride substituents attached to the metal. A variety of similar compounds are known, including Cp2TiCl2.
Organozirconium chemistry is the science of exploring the properties, structure, and reactivity of organozirconium compounds, which are organometallic compounds containing chemical bonds between carbon and zirconium. Organozirconium compounds have been widely studied, in part because they are useful catalysts in Ziegler-Natta polymerization.
Zirconocene dichloride is an organozirconium compound composed of a zirconium central atom, with two cyclopentadienyl and two chloro ligands. It is a colourless diamagnetic solid that is somewhat stable in air.
Organovanadium chemistry is the chemistry of organometallic compounds containing a carbon (C) to vanadium (V) chemical bond. Organovanadium compounds find only minor use as reagents in organic synthesis but are significant for polymer chemistry as catalysts.
Zirconium(III) chloride is an inorganic compound with formula ZrCl3. It is a blue-black solid that is highly sensitive to air.
In organometallic chemistry, bent metallocenes are a subset of metallocenes. In bent metallocenes, the ring systems coordinated to the metal are not parallel, but are tilted at an angle. A common example of a bent metallocene is Cp2TiCl2. Several reagents and much research is based on bent metallocenes.
Titanium ethoxide is a chemical compound with the formula Ti4(OCH2CH3)16. It is a commercially available colorless liquid that is soluble in organic solvents but hydrolyzes readily. Its structure is more complex than suggested by its empirical formula. Like other alkoxides of titanium(IV) and zirconium(IV), it finds used in organic synthesis and materials science.
(Cyclopentadienyl)titanium trichloride is an organotitanium compound with the formula (C5H5)TiCl3. It is a moisture sensitive orange solid. The compound adopts a piano stool geometry.
Hafnocene dichloride is the organohafnium compound with the formula (C5H5)2HfCl2. It is a white solid that is sparingly soluble in some organic solvents. The lighter homologues zirconacene dichloride and titanocene dichloride have received much more attention. While hafnocene is only of academic interest, some more soluble derivatives are precatalysts for olefin polymerization. Moreso than the Zr analogue, this compound is highly resistant to reduction.
The +4 oxidation state dominates titanium chemistry, but compounds in the +3 oxidation state are also numerous. Commonly, titanium adopts an octahedral coordination geometry in its complexes, but tetrahedral TiCl4 is a notable exception. Because of its high oxidation state, titanium(IV) compounds exhibit a high degree of covalent bonding.
Hafnium compounds are compounds containing the element hafnium (Hf). Due to the lanthanide contraction, the ionic radius of hafnium(IV) (0.78 ångström) is almost the same as that of zirconium(IV) (0.79 angstroms). Consequently, compounds of hafnium(IV) and zirconium(IV) have very similar chemical and physical properties. Hafnium and zirconium tend to occur together in nature and the similarity of their ionic radii makes their chemical separation rather difficult. Hafnium tends to form inorganic compounds in the oxidation state of +4. Halogens react with it to form hafnium tetrahalides. At higher temperatures, hafnium reacts with oxygen, nitrogen, carbon, boron, sulfur, and silicon. Some compounds of hafnium in lower oxidation states are known.