Discovery of the selenotantalate building block and its lanthanide derivatives: design, synthesis, and RhB decolorization properties

Recently, we demonstrated that the in situ formation of a building block is an attractive synthesis strategy for creating novel clusters with controllable structures. Herein, we present the design and synthesis of the first tantaloselenite polyoxoanion [Se₄(TaO₂)₆(OH)₄O₁₇]^4- (1) and a series of lanthanide derivatives (RE³⁺ = Tb³⁺, Dy³⁺, Ho³⁺, Er³⁺, Tm³⁺, Yb³⁺). In total, we report seven clusters that vary in both composition and structure but which share the same {Se₄(TaO₂)₆} building block. The compounds are fully characterized by single-crystal X-ray diffraction, IR spectra, TG, and PXRD and their decolorization properties for RhB have also been investigated. Compound 1 exhibits good photocatalytic activity for the decolorization of RhB while the introduction of lanthanide into the framework can also maintain this activity.