Design and synthesis of {CaCo₃}-based sandwich-type polyoxometalate

Abstract

A {CaCo₃}-containing sandwich-type polyoxometalate, Li₂Na₂Ca₃(H₂O)₁₆{Co₃(H₂O)[Ca(H₂O)₅PW₈O₃₁](PW₉O₃₄)}·16.5H₂O (1), was synthesized by using a trivacant phosphotungstate to react with Co²⁺ and Ca²⁺ by a conventional aqueous solution method. 1 was characterized by single crystal X-ray diffraction, powder X-ray diffraction, IR spectra, elemental analyses and TG analyses. Structural analysis reveals that 1 is composed of trivacant and a tetravacant phosphotungstates to trap a {Co₃} cluster and a Ca²⁺ cation. The obtained sandwich-type polyoxoanion was further connected to form a two-dimensional expanded structure via the Ca²⁺ linkers. This work highlights an efficient method to simultaneously introduce both alkaline-earth and transition-metal cations into polyoxotungstates.

Graphical Abstract

Keywords:

• Polyoxometalate
• transition metal
• alkaline earth metal
• photocatalytic

Additional information

Funding

This work was supported by the Major science and technology special projects of Henan Province (Grant No. 182102310873), Key Science Research Project of Colleges and Universities in Henan Province (Grant No. 18A150019) and 2019 Special Project of Nanyang Normal University (Grant No. 2019ZX009).