Dichloroiodomethane

Dichloroiodomethane (DCIM) is a trihalomethane with the chemical formula CHCl2I. It is a heavy, nonflammable, transparent pale yellow liquid with a chloroform-like odour. DCIM is soluble in organic solvents like acetone, diethyl ether, ethanol and benzene. It decomposes in contact with air and light. It has been detected in disinfected tap water and is considered to be a contaminant. DCIM has an estimated half-life of 275 years in water.

It was discovered by Georges-Simon Serullas in 1824, two years after his discovery of iodoform.

Synthesis
Many synthesis routes are known. Reaction of chloroform with sodium iodide or iodoethane gives dichloroiodomethane. Older methods include distillation of iodoform with phosphorus pentachloride or mercuric chloride.