ASb2(SO4)2(PO4) (A = H3O+, K,Rb): Layered Structure Containing Ordered Sulfate and Phosphate Anions

Three compounds ASb₂(SO₄)₂(PO₄) (A = H₃O⁺, K, Rb) were obtained from the reactions of Sb₂O₃, A₂CO₃ (A = Li, Rb) or K₂SO₄ and NH₄H₂PO₄ in H₂SO₄ (98 %) at 220–250 °C. Their structures were determined by single‐crystal X‐ray diffraction. All compounds crystallize in the triclinic space group P$\bar{1}$ (no.2) and are isostructural. The crystal structures consist of two‐dimensional ²_∞Sb₂(SO₄)₂(PO₄)]^– anionic layers and alkali cations, which are located between anionic layers. The anionic layers are composed of SbO₄] ψ‐trigonal bipyramids, SbO₅] ψ octahedra, SO₄] tetrahedra, and PO₄] tetrahedra. All compounds are characterized by solid state UV/Vis/NIR diffuse reflectance spectra, FT‐IR spectroscopy, and Raman spectroscopy.