Solvothermal Syntheses of Two Novel Layered Quaternary Silver−Antimony(III) Sulfides with Different Strategies

Two new silver antimony sulfides, KAg2SbS3 (1) and K2Ag3Sb3S7 (2), have been synthesized solvothermally in the presence of thiophenol as a mineralizer. Compound 1 contains a hexagonal net formed by condensation of Ag2SbS3 six-membered rings. These sheets are linked through Ag−S bonds to obtain double layers. The structure of 2 consists of infinite [Sb2S4]2− chains and [Ag6Sb2S10]∞8− columns linked to form layers. The [Sb2S4]∞2− chains are generated by vertex-shared SbS33− pyramids, while [Ag6Sb2S10]∞8− columns are composed of edge-shared of SbS3 pyramid, AgS3 triangles, and a AgS4 tetrahedron, and contain a Ag3SbS3 semicube. The optical band gaps of the two compounds are 2.1 and 2.2 eV, respectively.