Polymer Cu2+ and Ag+ furancarboxylate complexes with 4,4'-bipyridine: synthetic approaches, structure, thermal behavior, and biological activity.

Polymer complexes of the composition {[Cu2(fur)4(bpy)]n • nMeOH} (1) and {[Ag3(fur)(bpy)4]n•2nfur·13.5nH2O} (2) were synthesized by the reactions of copper(ii) and silver(i) acetates, respectively, with anions of furancarboxylic acid (Hfur) and 4,4'-bi-pyridine (bpy) under different synthesis conditions. The structures of the new complexes were established by X-ray diffraction (XRD) analysis. According to the XRD data, complex 1 is a polymer, in which the molecular metal oxide moieties are connected in a monodentate manner through bpy to form a 1D structural motif. The coordination environment of the copper(ii) atom in complex 1 can be described as a square pyramid {CuO4N}; the coordination number is 5. ionic complex 2 contains three nonequivalent Agi atoms in different coordination environment with different coordination numbers of the complexing metal (CNAg(1) = 4; CNAg(2)Ag(3) = 2). The supramolecular level of complex 2 is a 3D structure stabilized by different types of interactions, such as hydrogen bonds, π-stacking and ar-gentophilic interactions. The simultaneous thermal analysis demonstrated that complex 1 undergoes desolvation and decarboxylation at temperatures below 234 °C, whereas the bipyridine moieties coordinated to the copper(ii) atoms are not completely eliminated even at 500 °C. The in vitro biological activity of complexes 1 and 2 was evaluated against the non-pathogenic mycobacterial strain Mycolicibacterium smegmatis. [ABSTRACT FROM AUTHOR]