Papers by Author: K.K. Andjelković

Abstract: New complexes of Pt(II) with condensation derivatives of ethyl hydrazinoacetate and either 2-acetylpyridine or 2-quinolinecarboxaldehyde, and of Pd(II) with the condensation derivative of ethyl hydrazinoacetate and 2-quinolinecarboxaldehyde were synthesized and characterized by elemental analysis, IR, 1H- and 13C-NMR spectroscopy, and molar conductivity measurements. The complexes have a square planar geometry, ligands binding as bidentates in the neutral form, and the remaining two coordination sites being occupied by chloride ions. Biological activity of new complexes, and of previously synthesized Pd(II), Cd(II), Co(III) and Zn(II) complexes with this ligand type was evaluated by the brine shrimp test. All the complexes showed a moderate activity.

Abstract: Cytotoxic activity of four series of coordinated complexes of Zn(II) and Fe(II) with hydrazone/hydrazide ligands against HeLa and B16 cells was evaluated. The ligands N’,N'2- bis[(1E)-1-(2-pyridyl)ethylidene]ethanedihydrazide (H2L1) and N’,N'2-bis[(1E)-1-(2-pyridyl) ethylidene]propanedihydrazide (H2L2) and their Zn(II) complexes showed IC50 values in the low micromolar range, while the other ligands and complexes were less active or inactive.

Abstract: Thermal stability of neutral Zn(II), Pd(II) and Pt(II) complexes of formulae [Zn(apsox)2]·3H2O and [M(apsox)Cl] (M=Pd(II), Pt(II), HL=(E)-2-oxo-2-{N ’-[1-(pyridin-2- yl)ethylidene]hydrazino}acetamide) were studied. The results of DSC and TG analyses within the temperature range from 20 to 600 °C in nitrogen atmosphere showed that the loss of crystal water represents the first step during decomposition of the octahedral Zn(II) complex followed by structural rearrangement of its anhydrous form. After that the complex remained stable to about 330 °C. Different from neutral square-planar Pd(II) and Pt(II) complexes, a satisfactory resolution of the peaks in DSC of the Zn(II) complex enabled determination of the activation energies of its structural transformation and thermal degradation.