Syntheses, crystal structures and optical properties of the first strontium selenium(IV) and tellurium(IV) oxychlorides: Sr3(SeO3)(Se2O5)Cl2 and Sr4(Te3O8)Cl4

Two new quaternary strontium selenium(IV) and tellurium(IV) oxychlorides, namely, Sr3(SeO3)(Se2O5)Cl2 and Sr4(Te3O8)Cl4, have been prepared by solid-state reaction. Sr3(SeO3)(Se2O5)Cl2 features a three-dimensional (3D) network structure constructed from strontium(II) interconnected by Cl−, SeO32− as well as Se2O52− anions. The structure of Sr4(Te3O8)Cl4 features a 3D network in which the strontium tellurium oxide slabs are interconnected by bridging Cl− anions. The diffuse reflectance spectrum measurements and results of the electronic band structure calculations indicate that both compounds are wide band-gap semiconductors.

Graphical abstractSolid-state reactions of SrO, SrCl2, and SeO2 or TeO2 in different molar ratios and under different temperatures lead to two new strontium selenium(IV) or tellurium(IV) oxychlorides with two different types of structures, namely, Sr3(SeO3)(Se2O5)Cl2 and Sr4(Te3O8)Cl4. Both compounds are wide band-gap semiconductors based on the diffuse reflectance spectra and the electronic band structures.Figure optionsDownload full-size imageDownload as PowerPoint slide