Aluminum-Substituted Keggin Germanotungstate [HAl(H2O)GeW11O39]4-: Synthesis, Characterization, and Antibacterial Activity.

Elias Tanuhadi,Mathea Sophia Galanski,Alexander Prado-Roller,Nadiia I Gumerova,Hana Čipčić-Paljetak,Annette Rompel,Donatella Verbanac

doi:10.1021/acs.inorgchem.0c03311

Elias Tanuhadi, Mathea Sophia Galanski + Show 5 more

Open Access

https://doi.org/10.1021/acs.inorgchem.0c03311

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Journal: Inorganic chemistry	Publication Date: Dec 17, 2020
Citations: 20	License type: cc-by

Affiliation: University of Vienna, University of Zagreb

Abstract

We report on the new monosubstituted aluminum Keggin-type germanotungstate (C4H12N)4[HAlGeW11O39(H2O)]·11H2O ([Al(H2O)GeW11]4–), which has been synthesized at room temperature via rearrangement of the dilacunary [γ-GeW10O36]8– polyoxometalate precursor. [Al(H2O)GeW11]4– has been characterized thoroughly both in the solid state by single-crystal and powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and elemental analysis as well as in solution by cyclic voltammetry (CV) 183W, 27Al NMR and UV–vis spectroscopy. A study on the antibacterial properties of [Al(H2O)GeW11]4– and the known aluminum(III)-centered Keggin polyoxotungstates (Al-POTs) α-Na5[AlW12O40] (α-[AlW12O40]5–) and Na6[Al(AlOH2)W11O39] ([Al(AlOH2)W11O39]6–) revealed enhanced activity for all three Al-POTs against the Gram-negative bacterium Moraxella catarrhalis (minimum inhibitory concentration (MIC) up to 4 μg mL–1) and the Gram-positive Enterococcus faecalis (MIC up to 128 μg mL–1) compared to the inactive Al(NO3)3 salt (MIC > 256 μg mL–1). CV indicates the redox activity of the Al-POTs as a dominating factor for the observed antibacterial activity with increased tendency to reduction, resulting in increased antibacterial activity of the POT.

Highlights

Room temperature via has been characterized thoroughly both in the solid state by single-crystal and powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and elemental analysis as well as in solution by cyclic voltammetry (CV) 183W, 27Al NMR and UV−vis spectroscopy
CV indicates the redox activity of the aluminum(III)-centered Keggin polyoxotungstates (Al-POTs) as a dominating compared to factor for the the inactive Al(NO3)[3] salt
Polyoxometalates (POMs)[1] represent a broad class of anionic inorganic clusters with versatile structural topologies resulting in a variety of chemical and physical properties that can be modulated by molecular design

Summary

Introduction

Room temperature via has been characterized thoroughly both in the solid state by single-crystal and powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and elemental analysis as well as in solution by cyclic voltammetry (CV) 183W, 27Al NMR and UV−vis spectroscopy. Aluminum(III)-centered Keggin polyoxotungstates (Al-POTs) α([Al(AlOH2)W11O39]6−) revealed enhanced activity for all three Which incorporates an aluminum(III) metal center and crystallizes as the pure tetramethylammonium (TMA) salt (CCDC 1936850) in a 20% yield based on tungsten (procedure 1).

Results

Conclusion