Copper (II) complexes with commercial antibiotics, amoxicillin (AMX), azithromycin (AZT) and ciprofloxacin (CFL) were synthesized and isolated as solids. Structures of the isolated products were determined by FTIR spectroscopy. Antibacterial activities were determined on reference bacterial strains from the ATCC collection by diffusion technique. The results show that AMX and CFL coordinate Cu (II) ion as bidentate O-donor ligand. AZT coordinates metal center as bidentate NO-donor ligand. A difference in the morphology of antibiotic crystals and the synthesized complexes was found. Complex of Cu (AMX)2 show complete absence of antibacterial activity, while the other com-plexes show the same or even lower activity than the parent ligands.  

In this paper, three complexes with 8-hydroxyquinoline (8-HQ) were synthesized, their spectral analysis was performed and the antimicrobial effect was examined in vitro. The stoichiometric ratio of the complex was determined conductometrically and spectrophotometrically. FTIR and UV/VIS spectroscopy were used for structural characterization. Antimicrobial activity was examined by diffusion technique on selected gram-positive and gram-negative bacteria, and C. albicans. Square planar and octahedral geometry complexes were synthesized by mixing in a molar ratio of 1:2 (M:L). Based on the spectral data, it is concluded that both oxygen and nitrogen atoms from 8-HQ are involved in the formation of the complex. The antimicrobial activity of the complexes is high, with zones of inhibition in the range of 15 - 28 mm. 8-HQ was shown to have a significantly higher ability to inhibit the growth of the tested microorganisms.

Ciprofloxacin, CFL is a drug that belongs to the second generation of fluoroquinolone antibiotics with a wide range of effects on Gram-positive and Gram-negative bacteria. The aim of this work was to investigate the interaction of CFL as ligand with divalent biological cations (Mn2+, Ni2+ and Co2+) in approximate physiological conditions. Synthesized complexes were characterized using FTIR and stereo-microscopy. Antimicrobial screening was performed on bacterial strains of Escherichia coli, Salmonella Enteritidis, Enterococcus faecalis and Staphylococcus aureus. The results of FTIR spectroscopy showed that the M(II) complexes with CFL were formed through the oxygen donors of the carboxyl and carbonyl group of the ligand. Stereo-microscopic characterization revealed the difference in color and size of crystals of the ligand and metal complexes. Antimicrobial screening has shown that CFL and complexes have almost similar antimicrobial activity against investigated bacterial strains.