Ammonium bis(sulfamato) chlorocuprate

Formula: (NH₄)₂[Cu(SO₃NH₂)₂Cl₂]

An unusual coordination complex of copper, producing dark blue crystals.

Similar compounds: + Potassium bis(sulfamato) chlorocuprate, K₂[Cu(SO₃NH₂)₂Cl₂]. + Potassium bis(sulfamato) bromocuprate, K₂[Cu(SO₃NH₂)₂Br₂].

Properties

• Color: dark blue, almost black
• Crystal shape: tabular, flat
• Stability on air: stable

Preparation

Preparation is essentially the same as of the potassium analog, with potassium replaced by ammonium. However, there is a complication: a solution containing stoichiometric mixture of [NH₄]⁺, Cu²⁺, Cl^-, NH₂SO₃^- ions does not produce the desired compound upon crystallization. Instead, light blue crystals of ammonium tetrachlorocuprate appear. This can be solved by adding excess of copper sulfamate.

Safety

All copper compounds are moderately toxic.

More photos

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)