Synthesis, crystal structures of ASb(SO4)2 (A = K, Cs)

•Two new alkali antimony (III) sulfates have been synthesized.•The anionic structures of ASb(SO4)2 (A = K, Cs) exhibit different dimensionalities.•The ASb(SO4)2 (A = K, Cs) were characterized by IR spectra and solid state diffuse reflectance spectroscopy.

The reactions of A2SO4 (A = K, Cs) and Sb2O3 with H2SO4 (98%) yielded single crystals of ASb(SO4)2 (A = K, Cs). The crystal structures were investigated by single crystal X-ray diffraction. KSb(SO4)2 crystallizes in the monoclinic space group P21/c (No. 14) with lattice parameters a = 10.6745(18), b = 7.1579(12), c = 8.7597(15) Å, β = 91.466(3)°, V = 669.1(2) Å3, Z = 4. CsSb(SO4)2 crystallizes in the orthorhombic space group P212121 (No.19) with lattice parameters of a = 5.2429(8), b = 9.5942(16), c = 14.850(2) Å, V = 746.98(20) Å3, Z = 4. Both compounds show the Sb3+ cations in same seesaw-type coordination of oxygen atoms from different SO42−SO42− anions, but exhibit complex two-dimensionally and one-dimensionally linked anionic structures. The alkali cations are located between the layers or chains. The compounds were characterized with FT-IR spectra and solid state UV–vis–NIR diffuse reflectance spectroscopy. The band gaps were estimated at 4.64 eV for KSb(SO4)2 and 4.68 eV for CsSb(SO4)2.

Graphical abstractTwo alkali antimony (III) sulfates were prepared and characterized, anionic structures of KSb(SO4)2 and CsSb(SO4)2 are two dimensional layer structure and one dimensional chain, respectively.Figure optionsDownload full-size imageDownload as PowerPoint slide