Two new Keggin-type polyoxometalate-based organic-inorganic hybrid compounds with metal ions and chelate ligands

Two new hybrid compounds with chemical formulas [Co(L-1)(2)(H2O)(2)](2) [SiW12O40]center dot 6H(2)O (1) and [Cu-2(C9H22N)(2)(L-2)(2)][SiW12O40]center dot 2H(2)O (2) (L-1 = 3,3'-diamino-5,5'-bis(1H-1,2,4-triazole), L-2 = 1,2-bis(3-(2-pyridyl)pyrazole-1-ylmethyl)benzene, C9H22 N = tripropylamine) were prepared in a hydrothermal reaction system containing Keggin-type polyoxometalates (POMs), transition metal (TM) salts (cobalt salts and copper salts), and chelate L-1/L-2 ligands. X-ray structural analysis reveals that 1 and 2 possess 3-D supramolecular host frameworks with large cavities and the polyoxoanions SiW12 reside in these cavities as the guest templates. The photocatalytic activities of 1 and 2 were investigated. Both compounds show efficient catalytic activity for degradation of RhB with 1 > 2. The loading amount of the POM units and the structural features of these POM-based organic-inorganic hybrid compounds may be necessary factors that affect the activity of catalysts in the photocatalytic degradation. [GRAPHICS] .