Antimony trichloride

Antimony trichloride, also known as antimony(III) chloride or butter of antimony, is a chemical compound with the formula SbCl₃. It is a colorless or white crystalline solid that is highly soluble in water and other polar solvents. Antimony trichloride is used in various industrial applications, including as a catalyst and in the production of other antimony compounds.

Structure and Properties

Antimony trichloride is a molecular compound with a pyramidal structure. The central antimony atom is bonded to three chlorine atoms, forming a trigonal pyramidal shape due to the presence of a lone pair of electrons on the antimony.

The compound has a melting point of 73.4 °C and a boiling point of 223 °C. It is hygroscopic, meaning it readily absorbs moisture from the air, and it can form a hydrate when exposed to water.

Preparation

Antimony trichloride can be prepared by the direct chlorination of antimony:

\[ \text{2 Sb} + 3 \text{Cl}_2 \rightarrow 2 \text{SbCl}_3 \]

Alternatively, it can be produced by reacting antimony trioxide with hydrochloric acid:

\[ \text{Sb}_2\text{O}_3 + 6 \text{HCl} \rightarrow 2 \text{SbCl}_3 + 3 \text{H}_2\text{O} \]

Uses

Antimony trichloride is used in the chemical industry as a catalyst for polymerization and chlorination reactions. It is also employed in the production of flame retardants and as a mordant in dyeing processes.

In analytical chemistry, antimony trichloride is used as a reagent for detecting vitamin A and other unsaturated compounds.

Safety and Handling

Antimony trichloride is corrosive and can cause burns upon contact with skin or eyes. It should be handled with care, using appropriate personal protective equipment such as gloves and goggles. Inhalation of its vapors can be harmful, and it should be used in a well-ventilated area.

Also see

• Antimony
• Antimony pentachloride
• Antimony trioxide
• Chlorine
• Catalyst