| Objective To investigate the influence of reactive conditions on the structures of Keggin POM based metal-organic frameworks (MOFs) and the relations between structures and activities, nine new compounds were hydrothermally synthesized by tuning the reactive species and pH values.Methods POMOFs were hydrothermally synthesized and characterized by routine methods (IR and XPRD) and single-crystal X-ray crystallography. The antibacterial activities of the complexes were tested by the paper disc method. In addition, the photo luminescence properties of compounds were investigated in the solid state at room temperature.Results We systematically synthesis two series of POMOFs, namely, POM supporting metal-organic frameworks,[Ag6(2-pytz)4(H20)2][HPMo12040](1);{[Agi4(2-pytz)12(H2O)4]-[H4PMo12040]2}·2H20(2);{[Ag6(2-pytz)4(H2O)4][H2SiW12040)]}·6H20(3);{[Ag3(3-pytz)2]2-[AgPMo12040]}·2H20(4);[Ag6(4-pytz)4][HPMo12040](5); POM templated metal-organic frameworks, H[Ag6(2-pytz)4(H20)4][PW12040]·6H20(6);[Ag3(3-pytz)2[AgPW,2040](7); H[KAg7(4-pytz)5]-[SiW12040](8);{H[NaAg7(4-pytz)5(H20)0.5][GeMo12040]}2(9). We obtained the antibacterial diameter by the antimicrobial experiment of9kinds of compounds. In addition, photoluminescence properties of compounds were investigated in the solid state at room temperature. An emission maximum at470nm was observed for free ligands upon excitation at390nm, and the emission bands are probably attributable to the π*→π transitions. Compounds1-3display two emission bands at ca.440nm and ca.470nm when excitation occurs at390nm, which indicates that the emission of the free ligands were significantly affected by their incorporation into the Ag containing hybrid compounds. Compounds6-9display intense photoluminescence upon excitation at385nm, which are similar to those of the free ligands. So the origin of the emission of compounds can be tentatively attributable to the intraligand transition of the ligands.Conclusions Nine new Keggin POM supporting (or templated) MOF compounds with three kinds of smart pyridyltetrazoles ligands have been synthesized under hydrothermal conditions. These compounds display intriguing and versatile coordination features with isolated POM, pseudo POM chain, ture POM chain, pseudo POM layer, double-template,"Sandwich" and column-POM supporting (or templated) MOFs. The influences of the pH value, POM species and ligand isomers on the structures of the hybrid compounds have been investigated. The antibacterial experiments exhibit that compounds6-9have high antibacterial activity for E. coli and S. aureus. And reveal that POMOFs could be use to assembly bi-function and muti-function material by inherit their components. Since the compound is insoluble in water and common solvents such as ethanol, acetone, acetonitrile and benzene, it may be a good candidate for solvent-resistant green fluorescent material. |
