Significant Surface Modification of Polyoxometalate by Smart Silver-tetrazolate Units

Two interesting hybrids based on polyoxome-talates (POMs) and silver-tetrazolate subunits, H[Ag-11(pytz)(6)(H2O)(3)(P2W18O62)]center dot H2O (1), and H[Ag-17(pytz)(12)(H2O)(6) (PMo12O40)(2)] (2) pytz = 5-(2-pyridyl)tetrazolate), have been synthesized and structurally characterized. X-ray diffraction analysis reveals that the periphery of the Wells Dawson POMs contains 16 Ag-pytz subunits in compound 1, which represents the highest connection of the POMs up to now. In the crystal engineering point of view, all subunits, Ag atoms, POMs, and ligands, exhibit rich and novel coordination geometries, which facilitate the formation of the highest coordination number of the POMs. Compound 2 exhibits a complicated (6,12) connecting network with (3(6)4(6)5(3))(3(18)4(30)5(15)6(3)) topology and possesses close-packed structure due to the complementary coordination mode of PMo12a and PMo12b. To the best of our knowledge, this is a scarce coordination mode in one crystal. In addition, the luminescent properties and electrochemical behaviors of these compounds are discussed.