Syntheses, Structures And Antibacterial Activity Of Organic-inorganic Hybrid Heteropolytungstate With Keggin Structure

Objective Synthesized new Organic-inorganic Hybrid heteropolytungstate compounds and structurally characterized. To investigated the in-vitro antibacterial activity of novel compounds and the compounds which our group previously synthesized.Methods By conventional method in water solution, new Organic-inorganic Hybrid heteropolytungstate compounds have been synthesized. These compounds were further characterized by elemental analysis, IR and single crystal X-ray diffraction. We investigated the in vitro antibacterial activity of test compounds by slip method and tube double dilution method. (The test bacteria are escherichia coli, bacillus enteritidis, bacillus subtilis, pseudomonas qeruginosa, staphylococcus aureus, white staphylococcus and micrococcus ascoformans citreus.)Results Synthesized three new Organic-inorganic Hybrid heteropolytungstate compounds. And investigated the in vitro antibacterial of fourteen compounds which our group previously synthesized, there six compounds have antibacterial activity in vitro to the test bacteria. Finally, we get the Minimal Inhibitory Concentration and Minimal Bactericidal Concentration of the compounds which are sensitive to test bacteria.Conclusion Three new heteropolytungstate which are modified by imidazole have been designed and synthesized. The compound Na8{Cu(im)4(H2O)}[Cu(im)4{Na(H2O)2Co(im)}3(BiW9O33)2]·11H2O (im = imidazole) is composed by sandwich-type [{Na(H2O)2}3{Co(im)}3(BiW9O33)2]9- polyanion, mono-supported {Cu(im)4}2+ fragment, free Cu(II) fragment [Cu(im)4(H2O)]2+, sodium ions and free water molecules. The coordinated water molecules from Co2+ in central belt anion are functional by imidazole molecules, but the {Cu(im)4}2+ fragment linked terminal oxygen atom in the central anion and mono-supported on the extreme direction of heteropolyanion to formed a distortion square pyramidal structure. Compound Na3{Cu4(im)14(H2O)2}[{Na(H2O)}6{Cu(H2O)}3(XW9O33)2]·nH2O (X=Bi, Sb; n=22, 24) are heterogeneous isolog with each other. The Structure is composed by sandwich-type [{Na(H2O)2}3{Cu(H2O)}3(XW9O33)2]9- polyanion, two {Cu2(im)7}4+ fragments, free sodium ions and free water molecules. Two Cu2+ ions in {Cu2(im)7}4+ fragment linked two N atoms from one imidazole molecular and perpendicular to the axial direction of heteropolyanion. In this way, two {Cu2(im)7}4+ fragments which are located on the bipolar of anion liked two caps and linked by four terminals oxygen fromα–B–[BiW9O33]9- structure to form a quadr-supported structure. By our known, this kind of sandwich-type heteropolytungstate structure which is modified by quadr-supported copper compound is not reported. The antibacterial experiment indicated that some of Organic-inorganic Hybrid heteropolytungstate compounds with Keggin-structure could selectively inhibit the growth of text bacteria in vitro, and the inhibitory effect is significant to gram negative bacterium especially.