Bromine dioxide treatment of bromine gas with ozone in trichlorofluoromethane at −50 °C. When mixed with a base, bromine dioxide gives the bromide and bromate anions: Bromine dioxide Bromine dioxide is the chemical compound composed of bromine and oxygen with the formula BrO. It forms unstable yellow to yellow-orange crystals. It was first isolated by R. Schwarz and M. Schmeißer in 1937 and is hypothesized to be important in the atmospheric reaction of bromine with ozone. It is similar to chlorine dioxide, the dioxide of its halogen neighbor one period higher on the periodic table. Bromine dioxide is formed when an electric
Bromine weaker reducing agent than iodide, but a stronger one than chloride. These similarities led to chlorine, bromine, and iodine together being classified as one of the original triads of Johann Wolfgang Döbereiner, whose work foreshadowed the periodic law for chemical elements. It is intermediate in atomic radius between chlorine and iodine, and this leads to many of its atomic properties being similarly intermediate in value between chlorine and iodine, such as first ionisation energy, electron affinity, enthalpy of dissociation of the X molecule (X = Cl, Br, I), ionic radius, and X–X bond length. The volatility of bromine accentuates its