Coordination chemistry studies the formation and properties of complexes in which a central atom or ion is surrounded by ligands. In this diploma thesis, we selected the zinc(II) ion as the central ion and reacted it with furosemide. Furosemide is a pharmaceutical agent that contains functional groups capable of acting as donors in coordination with metal ions. It can coordinate to the metal centre either in a monodentate or bidentate manner via its deprotonated carboxyl group. The experimental work focused on the synthesis of zinc(II) coordination compounds with furosemide, their characterization, and the reproducibility of the reactions.
Different starting compounds were used in the synthesis, which influenced the final products. Reactions between zinc(II) oxide or chloride and furosemide in aqueous ammonia solution led to the formation of [Zn(fur)$_2$(NH$_3$)$_2$], where fur– represents the deprotonated furosemide. Sometimes mixtures with the (NH$_4$)fur salt were obtained. Reaction with [Zn(quin)$_2$(H$_2$O)] gave the coordination polymer [Zn$_3$(quin)$_4$(fur)$_2$]n∙2nMeOH, where quin– represents the quinaldinate. The reactions were carried out under different conditions at room temperature, under reflux and in an autoclave at 105 °C. Different solvent systems were also used. The choice of solvents was governed by the solubility of the reactants.
Compounds A, B and B·Et$_2$O were also synthesised in the diploma work but could not be identified.
The isolated products were characterised by infrared spectroscopy (IR), elemental CHN analysis, NMR spectroscopy and thermogravimetric analysis. The crystalline products were further analysed by single crystal X-ray structural analysis, which allowed the determination of their crystal structure.
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