Nitrogen tribromide is a chemical compound with the formula NBr3. It is extremely explosive in its pure form, even at −100 °C, and was not isolated until 1975. It is a deep-red and volatile solid.

Preparation

NBr3 was first prepared by reaction of bistrimethylsilylbromamine (bis(trimethylsilyl)amine bromide) with bromine monochloride (with trimethylsilyl chloride as byproduct) at −87 °C according to the following equation: where "Me" is a methyl group. NBr3 can be produced by the reaction of bromine or hypobromite and ammonia in a dilute aqueous buffer solution. It can also be prepared by the reaction of bromine and bromine azide. Ammonia and bromine undergo glow discharge, and after treatment, red NBr3·6NH3 can be obtained. Pure nitrogen NBr3 was only produced in 1975.

Reactions

Nitrogen tribromide reacts instantly with ammonia in dichloromethane solution at −87 °C to yield NBrH2. It also reacts with iodine in dichloromethane solution at −87 °C to produce NBr2I, which is a red-brown solid that stable up to -20 °C.