On the Crystal Structure of a Previously Unknown Anhydrous Zinc Hydroxide Sulfate

Anhydrous zinc hydroxide sulfates are promising precursors for the preparation of pigments and ZnO nanomaterials. The crystal structure of one such compound 5Zn(OH)₂] · 2ZnSO₄] was determined from high resolution laboratory X‐ray powder diffraction data by use of a combination of charge flipping, 18 simulated annealing, 26 and difference Fourier analysis. The material crystallizes in the space group P$\bar{1}$ with the lattice parameters of a = 5.4559(2) Å, b = 8.0528(3) Å, c = 8.9275(3) Å, α = 112.697(2)°, β = 85.219(3)°, γ = 95.441(3)°, and a volume of V = 359.76(2) ų. The basic crystal structure consists of brucite type Zn(OH)₂ layers where every sixth octahedral site is vacant. Tetrahedrally coordinated zinc ions are located above and below these vacancies and consecutive layers are bridged by sulfate molecules. The composition of this layered structure can be written as Zn₅^VI□(OH)₄ · Zn₂^IV(OH)₆ · (SO₄)₂]. Its thermal decomposition was studied by X‐ray powder diffraction and thermal analysis.