Halomethane the interaction of chlorine sources with various carbon compounds. The biosyntheses of these halomethanes are catalyzed by the chloroperoxidase and bromoperoxidase enzymes, respectively. An idealized equation is: Halons are usually defined as hydrocarbons where the hydrogen atoms have been replaced by bromine, along with other halogens. They are referred to by a system of code numbers similar to (but simpler than) the system used for freons. The first digit specifies the number of carbon atoms in the molecule, the second is the number of fluorine atoms, the third is the chlorine atoms, and the fourth is the number of bromine
Bromine thought that they could not exist at all. Dibromine monoxide is a dark-brown solid which, while reasonably stable at −60 °C, decomposes at its melting point of −17.5 °C; it is useful in bromination reactions and may be made from the low-temperature decomposition of bromine dioxide in a vacuum. It oxidises iodine to iodine pentoxide and benzene to 1,4-benzoquinone; in alkaline solutions, it gives the hypobromite anion. So-called "bromine dioxide", a pale yellow crystalline solid, may be better formulated as bromine perbromate, BrOBrO. It is thermally unstable above −40 °C, violently decomposing to its elements at 0 °C. Dibromine trioxide,