Hydrothermal synthesis of new mixed-oxoanion materials: Rare earth iodate sulfates Sm(IO3)(SO4) and Ln2(IO3)3(SO4)OH·3H2O (Ln = Sm, Eu, Dy)

Abstract

Chemical systems that contain non-centrosymmetric anions with electron lone pairs promote the formation of non-centrosymmetric phases. To probe this approach in mixed anion systems, we investigated crystallization in iodate-sulfate systems under mild hydrothermal conditions. By using different SO4 concentrations, the Sm(IO3)(SO4) and Ln2(IO3)3(SO4)OH·3H2O (Ln = Sm, Eu, Dy) structures were synthesized. It was observed that the reaction was very sensitive to the sulfate concentration. The structures were determined by single-crystal X-ray diffraction, where Sm(IO3)(SO4) crystallizes in the monoclinic crystal system adopting the space group P21/c and Ln2(IO3)3(SO4)OH·3H2O (Ln = Sm, Eu, Dy) crystallize in the triclinic crystal system adopting the space group P 1‾.