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
Chlorine its outer shell. Corresponding to periodic trends, it is intermediate in electronegativity between fluorine and bromine (F: 3.98, Cl: 3.16, Br: 2.96, I: 2.66), and is less reactive than fluorine and more reactive than bromine. It is also a weaker oxidising agent than fluorine, but a stronger one than bromine. Conversely, the chloride ion is a weaker reducing agent than bromide, but a stronger one than fluoride. It is intermediate in atomic radius between fluorine and bromine, and this leads to many of its atomic properties similarly continuing the trend from iodine to bromine upward, such as first ionisation energy,