AuSO4: A True Gold(II) Sulfate with an Au24+ Ion

Red single crystals of AuSO₄ have been obtained by evaporating a solution of Au(OH)₃ in concentrated sulfuric acid. The crystal structure (orthorhombic, Pbca, Z = 8, a = 854.9(2), b = 824.9(3), c = 1001.1(4) pm) exhibits the dumbbell shaped Au₂⁴⁺ cation (bond length Au–Au: 249 pm) which is coordinated by two chelating and two monodentate SO₄^2– groups. The monodentate sulfate anions act as chelating ligand to another Au₂⁴⁺ ion leading to infinite sheets according to (Au₂)(SO₄)_4/2] which are stacked in 001] direction.