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Three Schiff base Cu(II) complexes, (N,N’-bis(acetylacetone)­propyl­enediimine)copper(II) complex, [Cu(acac2pn)] (1), (N,N'-bis-(ben­zoyl­acet­one)propylenediimine)copper(II) complex, [Cu(phacac2pn)] (2) and (N,N’-bis-(trifluoroacetylacetone)propylenediimine)­copper(II) complex, [Cu(tfacac2pn)] (3), were used to investigate the interactions with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) using the electronic absorption and spectro­scopic fluorescence methods. UV–Vis absorption studies showed that studied complexes interact with DNA molecule and exhibit moderate binding affinity. Fluorescence studies of complexes 1–3 also showed a possibility for DNA int­ercalation as well as a relatively high binding ability toward BSA. Among the tested complexes, the highest affinity for DNA and BSA molecules was shown by complex 1. Cytotoxic analyses, performed on human colorectal carcinoma HCT-116 and healthy lung fibroblast MRC-5 cell lines, showed that complex 2 exhibited activity on both cell lines, while complexes 1 and 3 did not show any activity.

Cobalt(III) complexes derived from thio-and selenosemicarbazone ligands have been studied to elucidate the nature and consequences of S to Se substitution on their possible biological activity. Solid state structures of cobalt(III) complexes with bis-tridentate coordinated 2-quinolinecarboxaldehyde thio-and selenosemicarbazone were determined by single crystal X-ray diffraction analysis. The complexes were also characterized by spectroscopic methods and cyclic voltammetry. Electronic properties of the complexes were studied using DFT and TD-DFT methods. Finally, evident in vitro antioxidant activity of the complexes was demonstrated.

Cobalt(III) complexes derived from thio-and selenosemicarbazone ligands have been studied to elucidate the nature and consequences of S to Se substitution on their possible biological activity. Solid state structures of cobalt(III) complexes with bis-tridentate coordinated 2-quinolinecarboxaldehyde thio-and selenosemicarbazone were determined by single crystal X-ray diffraction analysis. The complexes were also characterized by spectroscopic methods and cyclic voltammetry. Electronic properties of the complexes were studied using DFT and TD-DFT methods. Finally, evident in vitro antioxidant activity of the complexes was demonstrated.

Cobalt(III) complexes derived from thio-and selenosemicarbazone ligands have been studied to elucidate the nature and consequences of S to Se substitution on their possible biological activity. Solid state structures of cobalt(III) complexes with bis-tridentate coordinated 2-quinolinecarboxaldehyde thio-and selenosemicarbazone were determined by single crystal X-ray diffraction analysis. The complexes were also characterized by spectroscopic methods and cyclic voltammetry. Electronic properties of the complexes were studied using DFT and TD-DFT methods. Finally, evident in vitro antioxidant activity of the complexes was demonstrated.

A gas-diffusion flow injection method with amperometric detection for the indirect determination of copper on a silver electrode was developed. The flow through system was equipped with two injection valves and a gas-diffusion unit. In the first step, a signal of a cyanide solution was recorded. In the subsequent step, the signal of cyanide in the presence of copper was measured. Interferences (Cd(II), Co(II), Ag(I), Ni(II), Fe(III), Hg(II) and Zn(II)) were investigated and successfully removed. The calibration graph was linear in the range 1-90 mu mol dm(-3) of copper with a correlation coefficient of 0.993. The regression equation is I = (0.0455 +/- 0.0015)c + (0.4611 +/- 0.0671), where I is the relative signal decrease in mu A and c is concentration in mu mol dm(-3). Relative standard deviation for six consecutive injections of 30 mu mol dm(-3) copper(II) was 1.47 % and for 1 mu mol dm(-3) copper(II), it was 3.40 %. The detection limit, calculated as 3 s/m (where s is a standard deviation of nine measurement of a reagent blank and m is the slope of the calibration curve), was 0.32 mu mol dm(-3), which corresponds to 2.44 ng of copper(II) (the loop volume was 0.12 cm(3)). The method enables 60 analyses per hour and it was successfully applied for the determination of copper in drinking water samples.

A selective and sensitive procedure for the fast and indirect determination of chloride by the gas-diffusion FIA method has been optimized and applied for the determination of chloride in water samples which contained different amounts of the analyte. The examined samples were: seawater, tap water and very pure water from the water-steam system of the power plant "Nikola Tesla B" in Obrenovac. Application of an amperometric detector (model LC-17A; BAS, West Lafayette, USA) enables the detection limit to be decreased down to 0.05 mu mol/dm(3) of chloride, which col responds to 35.5 pg, and adjustment of the acceptor flow rate and direction inside the gas-diffusion unit. In this way the optimized FIA system has excellent repeatability. For 5 mu mol/dm(3) it was found to be 1.11% (n = 5). The throughput of this method is 60 samples per hour.