Potassium bis(sulfamato) bromocuprate

Keywords: potassium, sulfamate, bromide, complex, copper

Formula: K₂[Cu(SO₃NH₂)₂Br₂]

Bromine analog of Potassium bis(sulfamato) chlorocuprate

Properties

• Crystal shape: thick rectangular tablets
• Color: very dark green, almost indistinguishable from black
• Stability on air: stable

Preparation

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].

Growing

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.

Safety

The main source of danger is copper: all copper compounds are moderately toxic.

More photos

When powdered, green coloration is observable:

References

• Préparation et étude par spectrométrie infrarouge de bis(sulfamato) halogénocuprate (II): M₂[Cu(NH₂SO₃)X₂](X = Cl ou Br et M = K ou NH4)