CuNHSO

CuNHSO, commonly referred to as copper ammonium sulfate, is a coordination compound with the chemical formula Cu(NH₃)₄SO₄. It is a blue crystalline solid that belongs to the class of copper-ammonia complexes, where copper(II) ions are coordinated with ammonia molecules. This compound is notable for its distinctive deep blue color, which arises from the d-d electronic transitions of the copper(II) ion in an octahedral coordination environment.

The synthesis of CuNHSO typically involves the reaction of copper(II) sulfate (CuSO₄) with ammonia (NH₃). When copper(II) sulfate pentahydrate is dissolved in water and ammonia is added, the formation of the complex occurs, often accompanied by a color change from blue-green to a more intense blue. The compound is soluble in water and exhibits properties typical of coordination complexes, such as ligand substitution reactions.

CuNHSO is primarily used in analytical chemistry as a reagent for detecting certain anions and cations. It serves as a qualitative test for the presence of sulfate ions (SO₄²⁻) and can also be employed in the identification of other ions through precipitation or colorimetric reactions. Additionally, it has been studied for its potential applications in electrochemistry and as a catalyst in specific organic reactions, though these uses are less common compared to its analytical role.

The compound is relatively stable under normal conditions but may decompose upon heating or exposure to strong acids, releasing ammonia and forming copper(II) sulfate again. Safety precautions should be taken when handling CuNHSO, as ammonia is corrosive and copper compounds can be irritating to skin and mucous membranes. Proper ventilation and protective equipment are recommended during handling and storage.