Copper(II) isopolytungstates in solution with acidity Z = 1.08; 1.17; 1.25; 1.33; 1.42

Abstract

In this master's thesis, the synthesis conditions of Tungsten (IV) compounds with Copper (II) cations from acidified aqueous solutions of sodium orthotungstate at different acidity values (Z = 1.08; 1.17; 1.25; 1.33; 1.42) were studied. As a result of the synthesis it was obtained double sodium-copper(II) paratungstate B Na2Cu4[W12O40(ОН)2]·22Н2О at acidity values Z = 1.08 and 1.17, and Na4Cu3[W12O40(ОН)2]·28Н2О – at Z = 1.25, the crystal structure of these compounds was previously determined. At higher values of acidity Z = 1.33 and 1.42 it was possible to isolate a new undescribed sodium-copper(II) paratungstate B Na6Cu2[W12O40(ОН)2]·31Н2О. The composition of the compounds was determined by chemical elemental analysis. The affiliation of salts to paratungstates B was founed on the base of FTIR spectroscopy results. Na6Cu2[W12O40(ОН)2]·31Н2О showed a high antibacterial activity against Escherichia coli ATCC 25922. As part of the antibacterial studies, the minimum inhibitory МІС = 500 µg∙mL –1 and the minimum bactericidal MBC = 700 µg∙mL -1 concentration were determined.