Zirconium tetrachloride

Chemical Properties

White, lustrous crystals. Sublimes above 300C. Soluble in alcohol; decomposes in water.

Chemical Properties

Zirconium tetrachloride forms lustrous, white, monoclinic crystals that melt at 437 ℃. It is a corrosive powder. It is hygroscopic, and thus soluble in cold water, alcohol, ether, and concentrated hydrochloric acid. It reacts vigorously with water forming hydrogen chloride (irritating vapor) and zirconium oxychloride. When moist, zirconium tetrachloride reacts with common materials to form hydrochloric acid that is corrosive to many metals. Through hydrolysis to HCl, zirconium tetrachloride can irritate the respiratory tract and other superficial surfaces of the body on exposure. Zirconium tetrachloride readily forms coordinate bonds with oxygen and nitrogen in organic molecules.

Physical properties

White monoclinic crystals; hygroscopic; density 2.80 g/cm³; sublimes at 331°C; triple point 437°C; vapor pressure 1 torr at 190°C; critical temperature 504.85°C; critical pressure 56.95 atm; critical volume 319 cm3/mol; decomposed by water; soluble in alcohol, ether, and concentrated hydrochloric acid.

Uses

Zirconium tetrachloride is commonly utilized as a Lewis acid catalyst in many organic synthesis reactions. It is an important source for organometallic complexes of zirconium. It is practiced in many areas like nuclear industry, metal industry, photography, glass, and ceramic industry.

Uses

Friedel-Crafts catalyst. Component of Ziegler-type catalysts in the condensation of ethylene. Starting material in the synthesis of a number of organic derivatives of zirconium, such as alkoxides and zircocene. The alkoxides have been shown to be of value in the curing of silicone plastic films. The alkoxyzirconium carboxylates are said to be useful in the water-repellent treatment of textiles and other fibrous materials.

Uses

Zirconium(IV) chloride (ZrCl4) is a Lewis acid catalyst, which has low toxicity. It is a moisture resistant material that is used as a catalyst in organic transformations.
ZrCl4 can be used as a catalyst for a variety of organic syntheses, such as Friedel-Crafts reaction, condensation reaction and other reduction reactions.

Uses

For applications in organozirconium chemistry.
1. Activates pyrrolidines for improved conversion, via a modified Bouveault reaction, to the corresponding α,α-dimethylamines.
2. Zirconium (IV) chloride is used as an efficient catalyst in the Pechmann condensation reaction of phenols with β‐keto esters leading to the formation of coumarin derivatives in good yields under solvent‐free conditions.

Preparation

Zirconium tetrachloride is obtained as an intermediate in recovering zirconium metal from zircon and other minerals (See Zirconium, Recovery). The tetrachloride is obtained by heating a mixture of zirconium hydroxide and car 1004 bon with chlorine gas
Also, tetrachloride can be made by reacting zirconium hydroxide with hydrochloric acid: Zr(OH)₄ + 4HCl → ZrCl₄ + 4H₂O.

Definition

ChEBI: Zirconium tetrachloride is a zirconium coordination entity comprising four chlorine atoms bound to a central zirconium atom. It has a role as a catalyst. It is a zirconium coordination entity and an inorganic chloride.

General Description

White lustrous crystalline solid. Used as a source of pure zirconium, as a tanning agent, in analytical chemistry and in treating textiles. Zirconium tetrachloride is decomposed by water. Corrosive to metals in the presence of moisture and to tissue.

Air & Water Reactions

Reacts vigorously with water forming hydrochloric acid with the evolution of heat.

Reactivity Profile

Zirconium tetrachloride is corrosive to metals in the presence of moisture and to tissue. Behavior in Fire: Will not burn - sublimes above 626°F (331°C). May give off HCl fumes [USCG, 1999]. Zirconium tetrachloride is incompatible with alcohols (ethanol), lithium metal, and tetrahydrofuran.

Health Hazard

INHALATION: Irritating to upper respiratory tract; presumably caused by liberated HCl. EYES: Irritating. SKIN: Irritating. INGESTION: Burning pain in the mouth and throat, vomiting, watery or bloody diarrhea, retching, collapse, and convulsions.

Fire Hazard

Behavior in Fire: Will not burn - sublimes above 626°F (331°C). May give off HCl fumes.

Flammability and Explosibility

Non flammable

Safety Profile

Moderately toxic by ingestion. A corrosive irritant to skin, eyes, and mucous membranes. Ignites spontaneously in air. When heated to decomposition it emits toxic fumes of Cl-. See also ZIRCONIUM COMPOUNDS and HYDROCHLORIC ACID.

Purification Methods

Crystallise it repeatedly from conc HCl. It is hydrolysed by H2O to form white ZrOCl2 (see below) and HCl. [Krebs Z Anorg Allgem Chem 378 263 1970.]