A bromide (Br ) is a chemical compound containing a bromide ion or ligand. This is a bromine atom with an ionic charge of −1 (Br−); for example, in caesium bromide, caesium cations (Cs+) are electrically attracted to bromide anions (Br−) to form the electrically neutral ionic compound CsBr. The term "bromide" can also refer to a bromine atom with an oxidation number of −1 in covalent compounds such as sulfur dibromide (S Br2).