Tin(IV) chloride

Tin(IV) chloride, also known as tin tetrachloride or stannic chloride is a chemical compound with the formula SnCl4. At room temperature it is a colourless liquid, which fumes on contact with air, giving a stinging odour. Its molecular weight is 260.5, its boiling point 114°C, and its freezing point -32°C. It is prepared from reaction of chlorine gas with elemental tin.

Anhydrous tin(IV) chloride is a strong Lewis acid which reacts violently with water. It is extremely corrosive to skin. On contact with air it releases severely irritating hydrogen chloride fumes. It forms a white pentahydrate, formerly known as butter of tin because of its consistency.

Stannic chloride was used as a chemical weapon in World War I. It is also used in the glass container industry for making an external coating containing tin(IV) oxide which toughens the glass. It is a starting material for organotin compounds.

Stannic chloride is used in chemical reactions with fuming (90%) nitric acid for the selective nitration of activated aromatic rings in the presence of unactivated ones.