Abstract
A proton transfer compound, (Hamp)+(Hdipic)− · 1.5H2O (1), and Cu(II) complexes, [Cu(dipic)(amp)(H2O)] · [Cu(dipic)(amp)] · H2O · CH3COOH (2) and [Cu(dipic)(amp)Cu(dipic)(amp)(H2O)Cu(dipic)(amp)(H2O)] · 3H2O (3), have been synthesized from 2,6-pyridinedicarboxylic acid (H2dipic) and 2-amino-4-methylpyridine (amp). They have been characterized by elemental, spectral (1H-NMR, IR, and UV-Vis), and thermal analyses. In addition, magnetic measurements and single crystal X-ray diffraction have been applied to 2 and 3. The crystal structure of 2 consists of two independent and different cationic sites with Cu2+ ions. Cu1 is four-coordinate in a distorted square planar geometry and Cu2 is five-coordinate in a distorted square pyramid. Compound 3 has three independent and different cationic sites of Cu2+ ions. Cu1 is four-coordinate in a distorted square planar geometry and Cu2 and Cu3 have five-coordinate, distorted square-pyramidal sites. Inhibitory effects of 1, 2, and 3 have been studied and compared with starting compounds (amp and H2dipic) on bacterial growth of Staphylococcus aureus and Escherichia coli cultures. Compounds 2 and 3 prevent bacterial growth although 1 has no effect. Compounds 2 and 3 are more effective than amp and H2dipic, at similar concentrations on preventing bacterial growth for both organisms.
Acknowledgments
The authors gratefully acknowledge the support provided by Dumlupınar University, Turkey (under grant no. 2007/2 of the University Research Fund). The also thank the Faculty of Arts and Sciences, Ondokuz Mayis University, Turkey, for using the Stoe IPDS-2 diffractometer purchased under grant F.279 of the University Research Fund.