Copper(II) Complexes with 5-Nitro-2-furoic Acid: Synthesis, Structure, Thermal Properties, and Biological Activity
К. А. Кошенскова, Irina А. Lutsenko, Yulia V. Nelyubina, Petr V. Primakov, Teimur M. Aliev, Olga B. Bekker, А. Хорошилов, S. N. Mantrov, Mikhail A. Kiskin, И.Л. Еременко
Abstract
Abstract Reaction of copper(II) acetate with 5-nitro-2-furoic acid (NO2-Hfur) and N-donor ligands 2,2'‑bipyridine (bpy) and pyridine (py) has resulted in complexes [Cu(NO2-fur)2(H2O)2]·2H2O (I), [Cu(NO2-fur)2(py)2(H2O)] (II), and binuclear [Cu2(NO2-fur)4(bpy)2]·H2O (III) whose structure was determined by X‑ray diffraction study. Cation Cu2+ is in square-planar (I) or square-pyramidal (II, III) environment and has CN(Cu) = 4 (I) or 5 (II, III), respectively. Stability of complexes I–III in solid phase has been determined by synchronous thermal analysis, stability in solutions has been studied by electronic absorption spectroscopy. Compounds I and II are thermally stable (>100°С). The presence of nitro group in the complexes causes strong exothermal effects, whose intensity is leveled by donor ligand. The storage of solutions of the compounds in 5% glucose solution and 0.9% NaCl for 2 days according to UV spectroscopy causes no their degradation. Biological activity of complexes I–III was studied in vitro toward non-pathogenic strain M. smegmatis (behaves as a model for M. tuberculosis); antimicrobial activity of compound II toward a number of Gram-positive and Gram-negative bacteria has been investigated.