Syntheses, Crystal Structures, Ion-Exchange, and Photocatalytic Properties of Two Amine-Directed Ge-Sb-S Compounds

Among numerous heterometallic chalcogenidoantimonates, relatively a few amine-directed Ge-Sb-S compounds have been synthesized. Presented here are the solvothermal syntheses, crystal structures, and ion-exchange, optical, and photocatalytic properties of two novel amine-directed Ge-Sb-S compounds, namely, [CH₃NH₃]₂₀Ge₁₀Sb₂₈S₇₂·7H₂O (1) and [(CH₃CH₂CH₂)₂NH₂]₃Ge₃Sb₅S₁₅·0.5(C₂H₅OH) (2). The structure of 1 features an unprecedented two-dimensional Ge-Sb-S double-layer composed of two twofold rotational symmetry-related thick [Ge₈Sb₂₈S₇₂]_n^28n- single layers adhered via vertex-sharing [GeS₄] tetrahedra. Compound 2 features a unique [Ge₃Sb₅S₁₅]_n^3n- slab perforated with large elliptic-like windows. Remarkably, compound 1 exhibited excellent Cs⁺ ion-exchange property despite the presence of excess competitive cations, such as Na⁺, K⁺, Mg²⁺, and Ca²⁺ ions. In addition, compound 1 displayed visible-light-driven photocatalytic activity for degradation of rhodamine B. (Figure Presented).