Syntheses Study of Keggin POM Supporting MOFs System

To investigate the influence of reactive conditions on the structures of Keggin POM supporting metal organic frameworks (MOFs), five new compounds, [Ag-6(2-pytz)(4)(H2O)(2)][HPMo12O40] (1), {[Ag-14(2-pytz)(12)(H2O)(4)][H4PMo12O40](2)}center dot 2H(2)O (2), {[Ag-6(2-pytz)(4)(H2O)(4)][H2SiW12O40)]}center dot 6H(2)O (3), {[Ag-3(3-pytz)(2)](2)center dot[AgPMo12O40]}center dot 2H(2)O (4), [Ag-6(4-pytz)(4)][HPMo12O40] (5) [pytz = 5-(pyridyl)tetrazolate], were hydrothermally synthesized by tuning the reactive species and pH values and characterized by routine method and single-crystal X-ray crystallography. Although compounds 1-5 all show the POM supporting 3D MOFs skeleton, MOFs exhibit diverse structures and POMs play different supporting functions, more specifically, pseudo POM chains supporting MOFs in 1 and 2, isolated POM spheres supporting MOFs in 3, ture POM chains supporting MOFs in 4, and pseudo POM layers supporting MOFs in S. The roles of the pH value, pytz derivatives, and the Keggin homologues in the formation of the POM supporting MOFs have been discussed. In addition, the photoluminescence properties of compounds 1-3 were investigated in the solid state at room temperature.