Bromine analog of Potassium bis(sulfamato) chlorocuprate
- Crystal shape: thick rectangular tablets
- Color: very dark green, almost indistinguishable from black
- Stability on air: stable
Prepare solution, containing potassium bromide KBr and copper sulfamate Cu(SO3NH2)2 in 2:1 molar ratio and crystallize it.
2KBr + Cu(NH2SO3)2 = K2[Cu(NH2SO3)2Br2].
Not the easiest material for growing. Has higher solubility compared to the chloride analog, and is more prone to forming parasite crystals. Moreover, solution has very dark color, making it impossible to control growth visually without extracting the crystal.
The main source of danger is copper: all copper compounds are moderately toxic.
When powdered, green coloration is observable: