C 2505 (OTTO) Copper(II) bromide Cas 7789-45-9 - used in photographic processing as an intensifier and as a brominating agent in organic synthesis. C 2505 (OTTO) Copper(II) bromide Cas 7789-45-9 - used in the coupling of o-iodophenols and aryl acetylenes avoiding the use of palladium.