1,2-Dibromotetrachloroethane (DBTCE) is an organohalide with the chemical formula . It is a crystalline solid that emits lachrymatory (tear-producing) vapours. Dibromotetrachloroethane can be used as a fungicide,[1] flame retardant[2] and a source for bromine in the laboratory.[3] Because the 1,1-dibromotetrachloroethane isomer is rare, 1,2-dibromotetrachloroethane is frequently referred to as simply dibromotetrachloroethane.
Dibromotetrachloroethane decomposes to Tetrachloroethylene and bromine when heated. Reacted with potassium sulphide, it gives tetrachloroethylene, potassium bromide and sulphur:
Dibromotetrachloroethane, when reacted with aniline at 140 to 150 °C, gives pure tetrachloroethylene.[4]
When reacted with compounds like cyclohexene, 2,2,4-trimethylpentl-ene, 1-hexene, 1-octene, 2-methyl-1-butene and 2,2,4-trimethyl-2-pentene, it yields allylic monobromides via bromination. Dibromotetrachloroethane loses both of its bromine atoms, leaving tetrachloroethylene and hydrogen bromide.[5]
Dibromotetrachloroethane was discovered by the Italian chemist Faustino Malaguti in 1846.[6] Malaguti exposed a mixture of Tetrachloroethylene (then known as chloréthose) and bromine to sunlight. It was named Bromure de chloréthose ("bromide of chlorethose") after its synthesis method.[7] Similar to Malaguti's method, modern synthesis of dibromotetrachloroethane uses bromine dissolved in carbon tetrachloride.