Mercury bromide is a mercury coordination entity composed of mercury and bromine with the formula HgBr2.Mercuric bromide appears as white rhombic crystals. Mercury(II) bromide (HgBr2) affords 1:1 adducts on reaction with N,N,N′,N′- tetramethyl-o-phenylenediamine. Single-crystal X-ray diffraction studies of these adducts have been reported. It forms complexes by reacting with 3,12-dimethylbenzo[a]quinoxalino[2,3-c]phenazine ligand.