dibromide

Dibromide is a term used in chemistry to describe a compound that contains two bromine atoms bound to a carbon skeleton, typically as a dihalide derived from hydrocarbons. Dibromides occur in two common structural forms: geminal (gem-dibromides), where both bromine atoms are attached to the same carbon, and vicinal (vic-dibromides), where the bromines are on adjacent carbons. These materials are often prepared by bromination of alkanes or alkenes and can serve as intermediates in organic synthesis.

Common examples include methylene dibromide (dibromomethane, CH2Br2), a gem-dibromide in which two bromine atoms are bonded to the same carbon, and 1,2-dibromoethane (ethylene dibromide, C2H4Br2), a vicinal dibromide formed by the addition of bromine to ethene. Other dibromides arise from more complex hydrocarbon frameworks and can vary widely in physical state and reactivity.

Properties of dibromides depend on structure and substituents but typically feature polar C–Br bonds. They can be reactive toward bases, undergo dehydrobromination to form alkenes, and participate in various coupling and substitution reactions in organic synthesis. Many dibromides are dense liquids or low-melting solids with notable odor and, in several cases, significant toxicity.

Safety and regulation are important considerations: several dibromides, including methylene dibromide and ethylene dibromide, are toxic and have been restricted or phased out for many uses due to health and environmental concerns. They are handled under appropriate safety protocols to prevent inhalation, ingestion, or dermal exposure.

See also: dihalides, brominated hydrocarbons, organic synthesis.