Bioisostere Modifications of Cu2+ and Zn2+ with Pyromucic Acid Anions and N-Donors: Synthesis, Structures, Thermal Properties, and Biological Activity

Abstract

Mono- and binuclear complexes [Cu(Fur)2(Phen)] (I), [Cu2(Fur)4(Py)2] (II), [Cu(Fur)2-(Py)2(H2O)] (III), and [Zn2(Fur)4L2] (L = Py (IV), Phpy (V)) are synthesized using the reactions of copper(II) and zinc(II) acetates with anions of pyromucic acid (2-furancarboxylic acid (HFur)) and N‑donor ligands (pyridine (Py), 4-phenylpyridine (Phpy), and 1,10-phenanthroline (Phen)) in acetonitrile. The copper complexes with pyridine are successively formed from the same reaction mixture: at first binuclear complex II is formed and then mononuclear complex III is formed. All compounds are isolated as single crystals, and their structures are determined by X-ray structure analysis (CIF files CCDC nos. 1974386 (I), 1974388 (II), 1974389 (III), 1974387 (IV), and 1974385 (V)). The thermal behavior of complexes II and III is studied by simultaneous thermal analysis. The biological activity in vitro of all complexes is determined toward the nonpathogenic mycobacterial strain Mycolicibacterium smegmatis. Complexes I and V exhibit a high biological activity and are promising for further studies of antitubercular activity.