Synthesis, Characterization, Crystal Structure and Biological Activities of Supramolecular Compounds of Mn(II) and Zn(II) With Dipicolinic Acid and 8-Hydroxyquinoline

Abstract

Two compounds,(8-H<inf>2</inf>Q)<inf>2</inf>[Mn(dipic)<inf>2</inf>] · 6H<inf>2</inf>O (1) and (8-H<inf>2</inf>Q)<inf>2</inf>[Zn(dipic)<inf>2</inf>] · 6H<inf>2</inf>O(2)(8-HQ = 8-hydroxyquinoline (oxine), H<inf>2</inf>dipic = dipicolinic acid), have been prepared and characterized by elemental, spectroscopic (IR and UV-Vis), and thermal analyses, magnetic measurements and single crystal X-ray diffraction techniques. Compounds 1 and 2 consist of two 8-hydroxyquinolinium cations, one bis(dipicolinato)M(II) anion (M =Mn(II) and Zn(II)) and six uncoordinated water molecules. Both 1 and 2 crystallize in the monoclinic space group C2/c. In the complex anion, each dipic ligand is tridentate through N of pyridine and oxygens of the carboxylate groups. Crystal packing of 1 and 2 is a composite of intermolecular hydrogen bonding interactions. The in vitro antibacterial and antifungal activities of 1 and 2 were evaluated by the agar well diffusion method by MIC (Minimal Inhibition Concentration), looking for compounds which display high-inhibitory effect against gram positive bacteria and fungi. No growth inhibition was observed against tested gram negative bacteria. © 2009 Taylor & Francis.