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Two square?planar complexes, [PtLCl] (1) and [PdLCl] (2), were synthesized with quinoline-2-carboxaldehyde thiosemicarbazone ligand (HL), and characterized by IR and NMR spectroscopy and single crystal X-ray diffraction analysis. In both complexes, L- is coordinated tridentately via the same donor atom set, while the fourth coordination site is occupied by a chloride ion. However, the complexes are not isostructural due to different types of non-covalent intermolecular interactions. These interactions were analyzed using Hirshfeld surfaces and two-dimensional fingerprint plots.

In this paper, Cu(II), Mn(II) and Zn(II) complexes with N,N,N-trimethyl-2-oxo-2-(2-(1-(thiazol-2-yl)ethylidene)hydrazinyl)ethan-1-aminium chloride (HL1Cl) were synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and DFT calculations. In all three complexes, a ligand (L1) is coordinated in a deprotonated formally neutral zwitterionic form via NNO donor set atoms. Cu(II) and Zn(II) form mononuclear penta-coordinated complexes [CuL1(N3)(CH3OH)]BF4 and [ZnL1(N3)2], respectively, while Mn(II) forms a binuclear [Mn2L12(μ-1,1-N3)2(N3)2]·2CH3OH complex, with unusual distorted trigonal-prismatic geometry around the metal centers. The antimicrobial activity of these complexes was tested against a panel of Gram-negative and Gram-positive bacteria, two yeasts and one fungal strain. The binuclear Mn(II) complex showed antifungal activity of similar intensity to amphotericin B. Based on the results of the brine shrimp test and DPPH radical scavenging activity, the most active Cu(II) and Mn(II) complexes were selected for evaluation of cytotoxic activity against five malignant cancer cell lines (HeLa, A375, MCF7, PC-3 and A549) and one normal cell line HaCaT. Both complexes showed significant activity. It should be pointed out that the activity of the Mn(II) complex against the MCF7 breast cancer cell line is only slightly weaker than that of cisplatin, but with selectivity to the tumor cell line in comparison to normal HaCaT cells, which is non-existent in the case of cisplatin. Supporting information: [https://cer.ihtm.bg.ac.rs/handle/123456789/4902] Related crystallographic data (CCDC 2110386): [https://cer.ihtm.bg.ac.rs/handle/123456789/4903] Related crystallographic data (CCDC 2110387): [https://cer.ihtm.bg.ac.rs/handle/123456789/4904] Related crystallographic data (CCDC 2110388): [https://cer.ihtm.bg.ac.rs/handle/123456789/4905]

In this work, Pt(II) complexes of previously synthesized steroidal thiosemicarbazones were synthesized and characterized. The ligands and their metal complexes were studied by analytical and spectroscopic data (elemental analysis, IR, 1D NMR and 2D NMR, HSQC, HMBC, NOESY, COSY), the analysis of which enabled complete 1H and 13C assignments of each compound including E and Z isomers. All the synthesized ligands and complexes were screened for their cytotoxic and antimicrobial activity. The results demonstrate that new steroidal thiosemicarbazone complexes were significantly less cytotoxic than corresponding steroidal thiosemicarbazones. Also, complexes show lower antimicrobial activity than the standard drugs, similar to the activity of the starting thiosemicarbazones. Почевши од претходно синтетисаних стероидних тиосемикарбазона, у овом раду су синтетисани и окарактерисани комплекси платине(II). Лиганди и њихови метални комплекси проучавани су аналитичким и спектроскопским методама (елементална анализа, ИЦ, 1D NMR и 2D NMR, HSQC, HMBC, NOESY, COSY). Анализом добијених података омогућена је потпуна 1H и 13C асигнација свих једињења укључујући Е и Z изомере. За синтетисане лиганде, као и њихове комплексе испитивана је цитотоксична и антимикробна активност. Резултати указују на то да нови стероидни тиосемикарбазонски комплекси испољавају значајно нижу цитотоксичност од одговарајућих стероидних тиосемикарбазона. Поред тога, комплекси поседују антимикробну активност сличну активности полазних тиосемикарбазона, a нижу од стандардних лекова

In this work synthesis, characterization and crystal structures of 1, Zn(II) complex ([ZnL1(NCS)2]), with (E)-1-(2-oxo-2-(2-(quinolin-2-ylmethylene)hydrazinyl)ethyl)pyridin-1-ium chloride (HL1Cl) and 2, Bi(III) complex ([BiHL2Cl4] × 1/2CH3OH), with (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(thiazol-2-yl)ethylidene)hydrazinyl)ethan-1-aminium chloride (HL2Cl), have been reported. Zn(II) complex possesses a distorted trigonal bipyramidal geometry while surroundings around Bi(III) ion are extended pentagonal bipyramidal. Antimicrobial activity, brine shrimp assay and DPPH radical scavenging activity of both complexes, including previously synthesized complexes with HL2Cl ligand (Zn(II) and Ni(II)) and complexes with (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium chloride (HL3Cl) (Zn(II), Cu(II), Cd(II), Co(II), Fe(III), Ni(II)), were evaluated. For the most active complexes, cytotoxic activity against five malignant cancer cell lines (HeLa, A375, MCF7, PC-3 and A549) and normal cell line HaCaT, as well as generation of reactive oxygen species (ROS), was tested. Supplementary material: [https://cherry.chem.bg.ac.rs/handle/123456789/4675]

The isothiocyanato Zn(II) complex (1) and mixed isothiocyanato/thiocyanato Cd(II) complex (2) with the condensation product of 2-acetylpyridine and trimethylammoniumacetohydrazide chloride (Girard’s T reagent) (HLCl) were investigated both experimentally and theoretically. The crystal structures of both complexes showed tridentate N2O coordination of hydrazine ligand. In complex 1 square-pyramidal coordination surrounding of Zn(II) consists of deprotonated hydrazone ligand and two isothiocyanato ligands, while in octahedral Cd(II) complex ligand is coordinated without deprotonation as a positively charged species and coordination geometry is completed with two N-coordinated and one S-coordinated NCS− anions. NMR spectroscopy and molar conductivity results for Cd(II) and Zn(II) complexes indicated their instability in solution. DFT calculations were performed to explain coordination preference and stability of complexes 1 and 2 in solid state and in solution. The obtained Cd(II) complex is the first reported mononuclear pseudohalide/halide Cd(II) complex with quinoline-/pyridine-based hydrazone ligands possessing octahedral geometry in solid state. In this complex, H-bonding has significant impact on coordination number and supramolecular assembly in solid state. © 2018, Springer Science+Business Media, LLC, part of Springer Nature. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3305]

The mixed chloride-azide [ZnL(N-3)(1.65)Cl-0.35] (1) and chloride-isocyanate [CdL(NCO)(1.64)Cl-0.36] (2) complexes with the condensation product of 2-quinolinecarboxaldehyde and trimethylammonium aceto-hydrazide chloride (Girard's T reagent) (HLCl) have been prepared and characterized by X-ray crystallography. In complexes 1 and 2, Znl and Cd1 ions, respectively, are five-coordinated in a distorted square based pyramidal geometry with NNO set of donor atoms of deprotonated hydrazone ligand and two monodentate ligands N-3(-) and/or N-3(-) and Cl- in the case of I and OCN- and/or OCN- and Cl- in the case of 2. The structural parameters of 1 and 2 have been discussed in relation to those of previously reported M(II) complexes with the same hydrazone ligand. Density functional theory calculations have been employed to study the interaction between the Zn2+ and Cd2+ ions and ligands. High affinity of ligands towards the Zn2+ and Cd2+ ions are predicted for both complexes. (C) 2018 Elsevier B.V. All rights reserved. This is peer-reviewed version of the following article: Anđelković, K.; Pevec, A.; Grubišić, S.; Turel, I.; Čobeljić, B.; Milenković, M. R.; Keškić, T.; Radanović, D. Crystal Structures and DFT Calculations of Mixed Chloride-Azide Zinc(II) and Chloride-Isocyanate Cadmium(II) Complexes with the Condensation Product of 2-Quinolinecarboxaldehyde and Girard’s T Reagent. Journal of Molecular Structure 2018, 1162, 63–70. [https://doi.org/10.1016/j.molstruc.2018.02.074]

This study presents the synthesis, characterization and antimicrobial activity evaluation of β-aminovinylphosphonium salts derived from aromatic amino acids. The compounds were prepared in the reaction of (formylmethyl)triphenylphosphonium chloride with various aromatic amino acids and their structures were determined by elemental analysis, IR and NMR spectroscopy. All synthesized compounds were tested for their antibacterial and antifungal activity.

In this article, synthesis, spectral and X-ray structure characterization, antimicrobial activity and Brine shrimp test of two new Cu(II) complexes with a salicylaldehyde derivative have been reported. Complexes [Cu(L)(bipy)]BF4·0.5H2O and [Cu2(L)2(phen)2](BF4)2 were obtained in the reaction of Cu(BF4)2·6H2O, deprotonated 4-(diethylamino)−2-hydroxybenzaldehyde ligand (L) and α-diimine (2,2’-bipyridine or 1,10-phenanthroline). The complex with bipyridine is mononuclear, containing one L and one bipyridine ligand in a distorted square-planar cation with a BF4 − anion and lattice water molecule, whereas the complex with phenanthroline is a dinuclear centrosymmetric dimeric cation, containing two L ligands along with two phenanthroline ligands and BF4 − anions. The coordination geometry of each Cu(II) ion can be described as an elongated square pyramid. MS-ESI spectroscopy indicated that [Cu2(L)2(phen)2](BF4)2 is mononuclear in DMSO solution. In vitro antibacterial and antifungal activity was tested against four Gram-positive, four Gram-negative bacteria and three fungal strains. Complexes showed significantly stronger antibacterial activities than parent ligands. The mononuclear phenanthroline complex in solution showed very good antimicrobial activity, which is comparable to the activity of the standard antibiotic amikacin against all tested bacterial strains. The same complex has better antifungal activity than fluconazole, which was used as a standard. Results of the brine shrimp test indicate that both complexes have good toxicity against Artemia nauplii. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/4026]

Two binuclear double end-on azido bridged Ni(II) complexes, [Ni2L2(μ-1,1-N3)2(N3)2]⋅2H2O (1a), and [Ni2L2(μ-1,1-N3)2(N3)2]⋅4H2O (1b) having the same inner sphere, where L=((E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(thiazol-2-yl)ethylidene)hydrazinyl)ethan-1-aminium, were synthesized from the same solution and characterized by single-crystal X-ray diffraction methods. Variable‐temperature magnetic susceptibility measurements showed intra-dimer ferromagnetic coupling between Ni(II) ions. The ferromagnetic coupling is supported by the broken-symmetry DFT calculations, with the level of theory chosen based on a benchmark study on 19 additional structurally related binuclear Ni(II) complexes. The role of water molecules in crystals of 1a and 1b is explained by DFT based energy decomposition analysis. This is the peer-reviewed, authors’ version of the article: Keškić, T.; Jagličić, Z.; Pevec, A.; Čobeljić, B.; Radanović, D.; Gruden, M.; Turel, I.; Anđelković, K.; Brčeski, I.; Zlatar, M. Synthesis, X-Ray Structures and Magnetic Properties of Ni(II) Complexes of Heteroaromatic Hydrazone. Polyhedron 2020, 191, 114802. [https://doi.org/10.1016/j.poly.2020.114802] Published version: [http://cer.ihtm.bg.ac.rs/handle/123456789/3684] Supplementary data: [https://cer.ihtm.bg.ac.rs/handle/123456789/4439] Crystallographic data (CCDC 2009327): [https://cer.ihtm.bg.ac.rs/handle/123456789/4441] Crystallographic data (CCDC 2009328): [https://cer.ihtm.bg.ac.rs/handle/123456789/4440]

Cobalt complexes with semi-and thiosemicarbazones of 8-quinolinecarboxaldehyde have been synthesized and characterized by X-ray diffraction analysis. These novel complexes and a previously synthesized cobalt complex with a selenium-based selenosemicarbazone ligand showed myeloid differentiation activity on all trans retinoic acid resistant HL-60 acute myeloid leukaemia cells. They also showed varying levels of cytotoxicity on five human tumor cell lines: cervix carcinoma cells (HeLa), lung adenocarcinoma cells (A549), colorectal adenocarcinoma cells (LS-174), breast carcinoma cells (MDA-MB-361), and chronic myeloid leukaemia (K562) as well as one normal human cell line: fetal lung fibroblast cells (MRC-5). Leukaemia differentiation was most strongly induced by a metal-free oxygen ligand and the selenium ligand, whilst the latter and the cobalt(II) complex with an oxygen ligand showed the strongest dose-dependent cytotoxic activity. In four out of five investigated tumor cell lines, it was of the same order of magnitude as cisplatin. These best compounds, however, had lower toxicity on non-transformed MRC-5 cells than cisplatin. This is the peer-reviewed version of the following article: Todorović, T. R.; Vukašinović, J.; Portalone, G.; Suleiman, S.; Gligorijević, N.; Bjelogrlić, S.; Jovanović, K.; Radulović, S.; Anđelković, K.; Cassar, A.; et al. (Chalcogen)Semicarbazones and Their Cobalt Complexes Differentiate HL-60 Myeloid Leukaemia Cells and Are Cytotoxic towards Tumor Cell Lines. MedChemComm 2017, 8 (1), 103–111. [https://doi.org/10.1039/c6md00501b] Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3093]

Two new Zn(II) complexes with tridentate hydrazone-based ligands (condensation products of 2-acetylthiazole) were synthesized and characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy and single crystal X-ray diffraction methods. The complexes 1, 2 and recently synthesized [ZnL3(NCS)2] (L3 = (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium) complex 3 were tested as potential catalysts for the ketone-amine-alkyne (KA2) coupling reaction. The gas-phase geometry optimization of newly synthesized and characterized Zn(II) complexes has been computed at the density functional theory (DFT)/B3LYP/6&ndash, 31G level of theory, while the highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO and LUMO) energies were calculated within the time-dependent density functional theory (TD-DFT) at B3LYP/6-31G and B3LYP/6-311G(d,p) levels of theory. From the energies of frontier molecular orbitals (HOMO&ndash, LUMO), the reactivity descriptors, such as chemical potential (&mu, ), hardness (&eta, ), softness (S), electronegativity (&chi, ) and electrophilicity index (&omega, ) have been calculated. The energetic behavior of the investigated compounds (1 and 2) has been examined in gas phase and solvent media using the polarizable continuum model. For comparison reasons, the same calculations have been performed for recently synthesized [ZnL3(NCS)2] complex 3. DFT results show that compound 1 has the smaller frontier orbital gap so, it is more polarizable and is associated with a higher chemical reactivity, low kinetic stability and is termed as soft molecule.

The reaction of (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium-chloride (HLCl) with copper(II) perchlorate led to mononuclear [CuLCl]ClO 4 complex (1). The same reaction with excess of sodium azide gives dinuclear azido double end-on bridged Cu(II) complex [Cu 2 L 2 (μ- 1,1 -N 3 ) 2 ](ClO 4 ) 2 (2). In both complexes hydrazone ligand is NNO coordinated in monodeprotonated formally neutral zwitter-ionic form. Complexes were characterized by elemental analysis, IR spectroscopy and single-crystal X-ray crystallography. Variable‐temperature magnetic susceptibility measurements for dinuclear Cu(II) complex showed intra-dimer ferromagnetic coupling between Cu(II) ions (J = 7.4 cm −1 ). DFT-BS calculations provided explanation for magnetic properties of dinuclear Cu(II) complex. Both complexes were shown to highly efficiently catalyze the N-arylation of imidazole and benzimidazole with electron-poor or electron-rich aryl iodides, under user-friendly and sustainable conditions. This is the peer-reviewed version of the following article: Milenković, M. R.; Papastavrou, A. T.; Radanović, D.; Pevec, A.; Jagličić, Z.; Zlatar, M.; Gruden, M.; Vougioukalakis, G. C.; Turel, I.; Anđelković, K.; et al. Highly-Efficient N-Arylation of Imidazole Catalyzed by Cu(II) Complexes with Quaternary Ammonium-Functionalized 2-Acetylpyridine Acylhydrazone. Polyhedron 2019, 165, 22–30. [https://doi.org/10.1016/j.poly.2019.03.001] Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3006]

A Pd(II) complex with methyl 2-((1-(2,4-dioxochroman-3-ylidene)ethyl)amino)acetate was synthesized. The structures of both the ligand and Pd(II) complex were determined by elemental analysis, IR and NMR spectroscopy. Recrystallization of Pd(II) complex from DMF/water solution resulted in its hydrolysis and formation of dimethylamine-(2-((1-(2,4-dioxochroman-3-ylidene)ethyl)amino)acetato)palladium(II) complex, the structure of which was determined by elemental analysis, IR, 1H and 13C NMR spectroscopy, as well as X-ray analysis. [Projekat Ministarstva nauke Republike Srbije, br. OI 172055 i br. OI 172016]

Octahedral Co(III) complexes with heteroaromatic hydrazones ((E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium chloride and (E)-2-(1-(thiazol-2-yl)ethylidene)hydrazine-1-carbothioamide) and tetraisothiocyanato Co(II) complex anions have been synthesized, characterized by elemental analysis, IR and NMR spectroscopy, single-crystal X-ray diffraction and magnetic measurements. NMR spectroscopy showed that octahedral Co(III) complex cations of both compounds are stable in DMSO solution. Measured effective magnetic moments, which completely originates from complex anion [Co(NCS)(4)](2-) are practically constant and very close to the expected value for Co2+ ion with spin S = 3/2 and completely quenched orbital angular momentum. Co(III) ions in octahedral complex cations are in a low spin magnetic state with S = 0 and do not contribute to the magnetic signal. This is the peer-reviewed version of the article: Čobeljić, B., Turel, I., Pevec, A., Jagličić, Z., Radanović, D., Anđelković, K.,& Milenković, M. R. (2018). Synthesis, structures and magnetic properties of octahedral Co(III) complexes of heteroaromatic hydrazones with tetraisothiocyanato Co(II) anions. Polyhedron, 155, 425-432. [https://doi.org/10.1016/j.poly.2018.08.070] The published version: [https://cer.ihtm.bg.ac.rs/handle/123456789/2374]

The isothiocyanato Fe(III) complex with (E)-N,N,N-trimethyl-2-oxo--2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium was synthesized and characterized by elemental analysis, IR spectroscopy and X-ray analysis. The octahedral geometry of the Fe(III) complex consists of the deprotonated form of the hydrazone ligand coordinated through the pyridine nitrogen, azomethine nitrogen and carbonyl oxygen atoms with three isothiocyanato ligands in the remaining coordination places. The measured effective magnetic moment for Fe(III) complex corresponds to high spin Fe(III) ion. The hydrazone ligand and its Fe(III) complex showed lower activity against the tested microbial strains than standard antimicrobial drugs. Supplamantary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3307]

A tridentate NNO condensation product of 2-quinolinecarboxaldehyde and Girard's T reagent (HLC1) in the presence of azide ions coordinates with cobalt(II) giving mononuclear azido Co(II) complex [CoHL (N-3)(3)](1) as a main product and dinuclear end-on azido bridged Co(II) complex [Co2L2(mu-(1,1)-N-3)(2)(N-3)(2)] (2) in traces. Crystal structures of both complexes were determined. Variable temperature magnetic susceptibility measurement studies of complex I showed that Co(II) cation is in the low-spin state with t(2g)(6)e(g)(1) (S = 1/2) configuration. DFT-BS calculations for complex 2 anticipated ferromagnetic type interaction between paramagnetic centers (J = 53 cm(-1)). (C) 2017 Elsevier Ltd. All rights reserved. This is peer-reviewed version of the following article: Romanović, M. Č.; Milenković, M. R.; Pevec, A.; Turel, I.; Spasojević, V.; Grubišić, S.; Radanović, D.; Anđelković, K.; Čobeljić, B. Crystal Structures, Magnetic Properties and DFT Study of Cobalt(II) Azido Complexes with the Condensation Product of 2-Quinolinecarboxaldehyde and Girard’s T Reagent. Polyhedron 2018, 139, 142–147. [https://doi.org/10.1016/j.poly.2017.10.018] Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3194]

In this work synthesis, characterization and crystal structures of two isothiocyanato Fe(III) complexes with 2,2'[2,6-pyridinediylbis(ethylidyne-1-hydraziny1-2-ylidene)]bis[N,N,N-trimethyl-2-oxoethanaminium] dichloride (H2LCl2) ligand, with composition [FeL(NCS)(2)]SCN center dot 2H(2)O and [FeL(NCS)(2)](2)[Fe(H2O)(NCS)(5)}4H(2)O, has been reported. Both iron(III) complexes possess the same pentagonal-bipyramidal complex cation, while the nature of their anions depends on mole ratio of NH4SCN and FeCl3 center dot 6H(2)O used in reaction. Cytotoxic activity of new Fe(III) complexes, as well as of previously synthesized isothiocyanato Co(II), Ni(II), Mn(II), Zn(II) and Cd(II) complexes with the same ligand, was tested against five human cancer cell lines (HeLa, MDA-MB-453, K562, LS174 and A549) and normal cell line MRC-5. The best activity was observed in the case of Fe(III), Co(II) and Cd(II) complexes. The investigation of potential of these complexes to induce HeLa and K562 cell cycle perturbations was also evaluated. Mechanism of cell death mode was elucidated on the basis of morphological changes of HeLa cells as well as identification of target caspases. It was established that DNA damage could be responsible for the activity of Fe(III) and Co(II) complexes. Synopsis: Pentagonal-bipyramidal Fe(III) complexes with dihydrazone of 2,6-diacetylpyridine and Girard's T reagent have been synthesized and characterized. Cytotoxic activity of Fe(III) complexes and Co(II), Ni(II), Mn (II), Zn(II) and Cd(II) complexes with the same ligand was tested. The best activity was observed in the case of Fe (III), Co(II) and Cd(II) complexes. This is the peer-reviewed version of the following article: Anđelković, K.; Milenković, M. R.; Pevec, A.; Turel, I.; Matić, I. Z.; Vujčić, M.; Sladić, D.; Radanović, D.; Brađan, G.; Belošević, S.; et al. Synthesis, Characterization and Crystal Structures of Two Pentagonal-Bipyramidal Fe(III) Complexes with Dihydrazone of 2,6Diacetylpyridine and Girard’s T Reagent. Anticancer Properties of Various Metal Complexes of the Same Ligand. Journal of Inorganic Biochemistry 2017, 174, 137–149. [https://doi.org/10.1016/j.jinorgbio.2017.06.011] Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3259]

Three square-planar complexes of nickel(II) with the tridentate condensation derivative of 2-(diphenylphosphino)benzaldehyde and ethyl carbazate, and monodentate pseudohalides, have been synthesized. Their crystal structures have been determined. All the complexes showed a significant antifungal activity, while only the azido complex displayed antibacterial activity. All the complexes were cytotoxic to a panel of six tumor cell lines, the azido complex showing a similar activity as cisplatin to leukemia cell line K562 and lower toxicity to normal MRC-5 cells than that anticancer agent. The complexes interfered with cell cycle of tumor cells and induced plasmid DNA cleavage. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3536]

A dinuclear double end-on azido bridged KM complex [Ni2L2(mu-(1),(1)-N-3)(2)(N-3)(2)] (1) with the condensation product of 2-quinolinecarboxaldehyde and trimethylammonium acetohydrazide chloride (Girard's T reagent) (HLCl) has been synthesized and characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction, magnetic measurements and DFT studies. In complex 1 intra-dimer ferromagnetic coupling between Ni2+ ions (J= +12.0(2) cm(-1)) and inter-dimer antiferromagnetic interaction (delta = -0.8(3) cm(-1)) were observed. DFT-BS calculations provided explanation of ferromagnetic exchange coupling in complex 1. This is the peer-reviewed version of the following article: Romanović, M. Č.; Čobeljić, B. R.; Pevec, A.; Turel, I.; Spasojević, V.; Tsaturyan, A. A.; Shcherbakov, I. N.; Anđelković, K. K.; Milenković, M.; Radanović, D.; et al. Synthesis, Crystal Structure, Magnetic Properties and DFT Study of Dinuclear Ni(II) Complex with the Condensation Product of 2-Quinolinecarboxaldehyde and Girard’s T Reagent. Polyhedron 2017, 128, 30–37. [https://doi.org/10.1016/j.poly.2017.02.039] Supplementary material:[http://cherry.chem.bg.ac.rs/handle/123456789/3101]

Two Zn(II) complexes with the condensation product of 2-quinolinecarboxaldehyde and trimethylammonium acetohydrazide chloride (Girard's T reagent) (HLCl) and monodentate pseudohalides (azide and cyanate) have been synthesized and characterized by elemental analysis, IR and NMR spectroscopy, and single-crystal X-ray diffraction. In both complexes, the coordination surroundings of the Zn(II) ions consist of a deprotonated hydrazone ligand coordinated through an NNO set of donor atoms and two monodentate pseudohalides (N-3(-) or NCO-) at the remaining coordination sites. The Zn(II) complexes showed low to moderate activity against laboratory control strains of pathogenic bacteria and fungi. [GRAPHICS] . Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3067] This is peer-reviewed version of the following article: Romanović, M. Č.; Čobeljić, B.; Pevec, A.; Turel, I.; Anđelković, K.; Milenković, M.; Radanović, D.; Belošević, S.; Milenković, M. R. Synthesis, Crystal Structures and Antimicrobial Activity of Azido and Isocyanato Zn(II) Complexes with the Condensation Product of 2-Quinolinecarboxaldehyde and Girard’s T Reagent. J. Coord. Chem. 2017, 70 (14), 2425–2435. [https://doi.org/10.1080/00958972.2017.1343945]

The chloro (1) and isocyanato (2) Cd(II) complexes with the condensation product of 2-quinolinecarboxaldehyde and trimethylammonium acetohydrazide chloride (Girard's T reagent) (HLCl) have been synthesized and characterized by elemental analysis, IR, and NMR spectroscopy. The crystal structure of chloro Cd(II) complex (1) was determined. In 1 and 2, coordination surrounding of Cd(II) consists of deprotonated hydrazone ligand coordinated through NNO-donor atoms and two monodentates at the rest of the coordination places. Quantum chemical calculations of the molecular structures and the relative stabilities of linkage isomers of the Cd(II) complex showed that the isomer with N-Cd-N coordination of OCN- is the most stable. The investigated Cd(II) complexes showed lower activity than standard antimicrobial drugs. [GRAPHICS] . This is the peer-reviewed version of the following article: Romanović, M. C.; Čobeljić, B.; Pevec, A.; Turel, I.; Grubišić, S.; Radanović, D. D.; Anđelković, K. K.; Milenković, M.; Milenković, M. R. Synthesis, Characterization, DFT Calculations and Antimicrobial Activity of Cd(II) Complexes with the Condensation Product of 2-Quinolinecarboxaldehyde and Girard’s T Reagent. Journal of Coordination Chemistry 2017, 70 (21), 3702–3714. [https://doi.org/10.1080/00958972.2017.1405262] [http://cer.ihtm.bg.ac.rs/handle/123456789/2109]

A new malonic dihydrazide-based ligand, N′,N′ 2-bis[(1E)-1-(2-quinolyl)methylene]propanedihydrazide (H2L3), has been prepared and characterized by elemental analysis, IR, 13C NMR, and 1H NMR spectroscopies. In the reaction of H2L3 with Ni(II) a binuclear complex has been obtained. The structure of the complex was established by X-ray analysis. Each Ni(II) is coordinated with two NNO donor sets from two ligand molecules in dianionic form (L32–) forming an octahedral geometry. Multiple intramolecular C–H ··· π (chelate ring) interactions support the molecular geometry of the [Ni2(L3)2] complex. The structure of [Ni2(L3)2] is compared with those of analogous Ni(II) complexes with pyridine dihydrazone type ligands. Magnetic behavior of the dinuclear complex was studied in temperature range of 2–300 K.

Multi-step thermal degradation of coordination polymer [Cd( N -Boc-gly) 2 (H 2 O) 2 ] n in non-isothermal conditions was studied. The kinetic parameters were determined from the thermal decomposition data using the isoconversion and non-isoconversion techniques. It was shown that the coordination polymer is stable up to 60 °C, when the multi-step process of thermal dehydration, followed by steps of degradation, starts. The kinetic triplet for the step of dehydration was established as f ( α ) = 3 / 2 ( 1 − α ) 2 / 3 [ 1 − ( 1 − α ) 1 / 3 ] − 1 , E inv = 170.4 ± 6.4 kJ mol −1 and Z inv = 2.6 × 10 23 . The established kinetic model, known as “D3 model”, was confirmed by application criteria defined by Malek, Perez-Maqueda et al. as well as Master plot method. Dehydration step is followed by two steps of dehydrated coordination polymer degradation. On the base of the dependence of Arrhenius parameters ( E a and Z ) on conversion degree ( α ), the mechanisms of degradation were discussed. In this way it was shown that second and third steps of degradation of coordination polymer are complex involving more than one elementary step. The second step corresponds to the loss of two C 6 H 5 CH 2 O– fragments in two parallel steps. The third step of degradation, ascribed to the loss of two –C( O)NHCH 2 – fragments, is complicated by changing kinetically to diffusion control.

The kinetics of multi-step thermal degradation of Co(II) complex with N-benzyloxycarbonyl glycinato ligand [Co(N-Boc-gly)(2)(H2O)(4)]center dot 2H(2)O, in non-isothermal conditions was studied using isoconversional and non-isoconversional methods. The degradation of complex occurs in three well-separated steps involving the loss of water molecules in first step followed by two degradation steps of dehydrated complex. The dependence of Arrhenius parameters on conversion degree showed that all observed steps of thermal degradation are very complex, involving more than one elementary step, as can be expected for most solid-state heterogeneous reactions with solid reactants and solid and gaseous products. It was shown that step 1, corresponding to the dehydration, involves a series of competitive dehydration steps of differently bound water molecules complicated by diffusion. Second step involves two parallel reactions related to the loss of two identical C6H5CH2O-ligand fragments complicated by the presence of products in gaseous state. Further degradation in step 3 corresponds to complex process with a change in the limiting stage, in this case from the kinetic to the diffusion regime, connected with the presence of gaseous products diffusing through the solid product.

For the first time, complexes of Zn(II), Cd(II) and Co(II) (1–3) with N-benzyloxycarbonylglycine have been synthesized and characterized. The complexes adopt tetrahedral, pentagonal-bipyramidal and octahedral geometry, respectively. The structure of the polymeric cadmium complex was resolved by single crystal X-ray analysis. The cadmium ion has a distorted pentagonal-bipyramidal coordination formed by two water molecules and two N-benzyloxycarbonylglycinato ligands (N-Boc) coordinated in different fashions, one as bidentate and the second connecting three cadmium atoms. In a rather complicated 2D supramolecular structure, the phenyl rings interact mutually exclusively by the CH⋯π interactions. Investigation of the antimicrobial activity of the obtained complexes and N-benzyloxycarbonylglycine revealed that the ligand does not inhibit the growth of Candida albicans, whereas the newly synthesized complexes suppress the growth of this human fungal pathogen.

Square-planar azido Ni(II) complex with condensation product of 2-(diphenylphosphino)benzaldehyde and Girard's T reagent was synthesized and its crystal structure was determined. Cytotoxic activity of the azido complex and previously synthesized isothiocyanato, cyanato and chlorido Ni(II) complexes with this ligand was examined on six tumor cell lines (HeLa, A549, K562, MDA-MB-453, MDA-MB-361 and LS-174) and two normal cell line (MRC-5 and BEAS-2B). All the investigated nickel(II) complexes were cytotoxic against all tumor cell lines. The newly synthesized azido complex showed selectivity to HeLa and A549 tumor cell lines compared to the normal cells (for A549 IC50 was similar to that of cisplatin). Azido complex interferes with cell cycle phase distribution of A549 and HeLa cells and possesses nuclease activity towards supercoiled DNA. The observed selectivity of the azido complex for some tumor cell lines can be connected with its strong DNA damaging activity. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3547]

Pentagonal-bipyramidal isothiocyanato Co(II) and Ni(II) complexes with condensation product of 2,6-diacetylpyridine and trimethylammoniumacetohydrazide (Girard's T reagent) were synthesized and characterized by elemental analyses, IR and UV-vis spectra, molar conductivity, and magnetic susceptibility. Crystal structures of the Co(II) and Ni(II) complexes were also determined. Antimicrobial activities of the ligand and metal complexes were examined. [GRAPHICS] . This is peer-reviewed version of the following article: Bradan, G.; Cobeljic, B.; Pevec, A.; Turel, I.; Milenkovic, M.; Radanovic, D.; Sumar-Ristovic, M.; Adaila, K.; Milenkovic, M.; Andelkovic, K. Synthesis, Characterization and Antimicrobial Activity of Pentagonal-Bipyramidal Isothiocyanato Co(II) and Ni(II) Complexes with 2,6-Diacetylpyridine Bis(Trimethylammoniumacetohydrazone). J. Coord. Chem. 2016, 69 (5), 801–811. [https://doi.org/10.1080/00958972.2016.1139702] Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3637]

Isothiocyanate complexes of Zn(II) and Cd(II) with the condensation product of 2,6-diacetylpyridine and trimethylammoniumacetohydrazide (Girard's T reagent) were synthesized, characterized, and their antimicrobial activities were evaluated. The structures of the complexes were determined by elemental analysis, IR, and NMR spectroscopy. The crystal structure of the Zn(II) complex was also determined. Quantum-chemical calculations of the geometry and total energy of isomers of 2,6-diacetylpyridine-bis(trimethylammoniumacetohydrazone) were performed in vacuum and methanol solution, with the aim to explain conformational behavior and E/Z isomerism of this compound. DFT calculations of the molecular structures and the relative stabilities of linkage isomers of the Cd(II) complex showed that the isomer with N-Cd-N coordination of SCN- is the most stable. Complexes of Zn(II) and Cd(II) exhibited low to moderate activity against the tested microbial strains. [GRAPHICS] This is the peer-reviewed version of the article: Gabrijela Brađan, Andrej Pevec, Iztok Turel, Igor N. Shcherbakov, Milica Milenković, Marina Milenković, Dušanka Radanović, Božidar Čobeljić & Katarina Anđelković (2016): Synthesis, characterization, DFT calculations and antimicrobial activity of pentagonal-bipyramidal Zn(II) and Cd(II) complexes with 2,6-diacetylpyridinebis(trimethylammoniumacetohydrazone), Journal of Coordination Chemistry, DOI: [http://dx.doi.org/10.1080/00958972.2016.1212339] The published version: [http://cer.ihtm.bg.ac.rs/handle/123456789/1922]

New complexes of Cd(II), Zn(II) and Ni(II) with 2-quinolinecarboxaldehyde selenosernicarbazone (Hqasesc) were synthesized and structurally characterized. The structure of the ligand, Cd(II) and Zn(II) complexes was determined by NMR and IR spectroscopy, elemental microanalysis and molar conductivity measurements. Both complexes occur in solution in two forms, the major tetrahedral and minor octahedral. In the major Cd(II) complex one qasesc(-) ligand is coordinated as a tridentate, the fourth coordination site being occupied by acetate, while in the major Zn(II) complex two qasesc- ligands are coordinated as bidentates. In both minor complexes two qasesc- ligands are coordinated as tridentates forming the octahedral geometry around the central metal ion. The only paramagnetic complex in the series is Ni(II) complex for which X-ray structure analysis was performed. The complex has the angularly distorted octahedral geometry with two qasesc- ligands coordinated as tridentates, in a similar way as in the minor complexes of Cd(11) and Zn(11). (c) 2007 Elsevier Ltd. All rights reserved.

A new palladium(II) complex I of the condensation product of 2-(diphenylphosphino)benzaldehyde (dpba) and ethyl hydrazinoace-tate (etha) was synthesized and characterized by elemental analyses, IR, and H-1 NMR spectroscopy. The bound ligand is a bidentate (PN chromophore), the remaining two coordination places being occupied by chloride ions in overall square planar geometry. The cytotoxic activity of the complex I and two related Pd(II) and Pt(II) complexes 2 and 3 was tested against a panel of four tumor cell lines. The activity of the complexes was similar to that of cisplatin, the most widely used metal-based antitumor drug. It is important to notice that complexes 2 and 3 were active to cisplatin-resistant U2-OS/Pt cells. Cell cycle alteration investigation, apoptotic assay and gelatin zymography in relation to invasion and metastasis of tumor cells, were performed with all the investigated complexes on Human cervix carcinoma (HeLa) cells. The results suggest that I has a similar effect to cisplatin, inducing apoptosis followed by arrest of cells in S phase of cell cycle, while 2 and 3 induce apoptosis without significant perturbations of cell cycle distribution. (c) 2006 Elsevier Inc. All rights reserved.

Four Co(III), Zn(II), Pd(II) and Cd(II) complexes with ligands derived in situ from acetylpyridine and ethyl hydrazinoacetate or hydrolysed ethyl hydrazinoacetate were prepared. An X-ray structural analysis showed that the Co(III) complex is octahedral with two tridentate (E)-2-[N′-(1-pyridin-2-yl-ethylidene)hydrazino]acetate (apha) ligands, each forming two five-membered rings with the metal ion. In the tetrahedral Zn(II) complex, only a single apha ligand was coordinated, in the same way as that in the Co(III) complex. In the case of the tetrahedral Cd(II) complex the non-hydrolysed form of (E)-2-[N′-(1-pyridin-2-yl-ethylidene)hydrazino]acetic acid ethyl ester (aphaoet) coordinated as a bidentate and the two remaining coordination sites were occupied by Cl− and CH3COO− ions. In addition, the square-planar neutral Pd(II) complex was synthesized, having the same bidentate as in the Cd(II) complex and two Cl− ions in the remaining coordination sites. Due to their being diamagnetic, all four complexes were ...

Square-planar isocyanate and chloride Ni(II) complexes with tridentate PNO condensation product of 2-(diphenylphosphino)benzaldehyde and Girard's T reagent have been synthesized and their crystal structures were determined. These Ni(II) complexes with different monodentate ligands, chloride, cyanate, and thiocyanate were tested for their antimicrobial activities against pathogenic microorganisms. The ligand and Ni(II) complexes were active not only against laboratory control strains of bacteria and yeast, but also on clinical isolates of Escherichia coli and Pseudomonas aeruginosa strains resistant to most of the clinically used antibiotics. This is the peer-reviewed version of the following article: Milenković, M. R.; Pevec, A.; Turel, I.; Milenković, M.; Čobeljić, B.; Sladić, D.; Krstic, N.; Anđelković, K. K. Synthesis, Crystal Structures, and Antimicrobial Activity of Square-Planar Chloride and Isocyanate Ni(II) Complexes with the Condensation Product of 2-(Diphenylphosphino)Benzaldehyde and Girard’s T Reagent. Journal of Coordination Chemistry 2015, 68 (16), 2858–2870. [https://doi.org/10.1080/00958972.2015.1055260] Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3447]

A Schiff base of 3-acetylpyridine with semicarbazide as well as the corresponding tetrahedral Zn(II) complex were synthesized and characterized by X-ray crystal structure analysis and spectroscopic methods. It is interesting to note that the ligand coordinated as a monodentate although there are several donor atoms in it. Computational studies showed that such structure is more stable than the hypothetical structure with one ligand bound as a bidentate. The complex exibited moderate antibacterial, antifungal and cytotoxic activities while the ligand was mostly inactive. The complex strongly induced formation of reactive oxygen species in tumor cell lines. It also influenced cell cycle progression in tumor cell lines, and induced autophagy. The latter effect is, at least in part, a protective one his work was supported by the Ministry of Education and Science of the Republic of Serbia (Grant OI 172055 and III41025). We thank the Slovenian Research Agency (ARRS) thrugh program P-0175 for financial support and EN-FIST Centre of Excellence, Dunajska 156, 1000 Ljubljana, Slovenia, for using SuperNova diffractometer. The following organizations are thanked for financial support: the Ministerio de Ciencia e Innovacion (MICINN, project number CTQ2011-25086/BQU), and the DIUE of the Generalitat de Catalunya (project number 2009SGR528). Financial support from MICINN (Ministry of Science and Innovation, Spain) and the FEDER fund (European Fund for Regional Development) was provided by grant UNGI08-4E-003. Excellent service by the Centre de Serveis Cientifics i Academics de Catalunya (CESCA) is gratefully acknowledged

Copper(II) and zinc(II) complexes with the condensation derivative of 2-acetylpyridine and hydrolyzed ethyl hydrazinoacetate were synthesized in a one pot reaction. Crystal structure of the zinc(II) complex was determined by single-crystal X-ray diffraction. In this binuclear complex, the ligand is coordinated via pyridine and imine nitrogen, while carboxylate oxygen is a bridge between metal centers. The fifth coordination site is occupied by a chloride, giving a distorted square pyramidal geometry around each zinc(II). The molecular structure of the copper(II) complex was determined from elemental analysis, infrared and electron paramagnetic resonance spectroscopy, molar conductivity, mass spectrometry, and measurements of the magnetic moment. Thermal behavior of both complexes was studied by thermogravimetric analysis coupled with mass spectrometer. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3538]

A cobalt(III) complex with the condensation derivative of 2-(diphenylphosphino) benzaldehyde and ethyl carbazate was synthesized. X-ray crystal structure was determined for both the ligand and the complex. In the cobalt(III) complex two deprotonated ligand molecules coordinate the metal atom in a distorted octahedral geometry by chelation through the PNO donor system formed by the phosphorus, the imine nitrogen and the carbonyl oxygen. The complex showed a moderate antibacterial activity and a strong cytotoxic activity, stronger than cisplatin. Based on cell cycle progression, apoptotic assays, spectroscopic and electrophoretic studies, it was shown that high cytotoxicity and moderate potential of induction of apoptosis are not consequence of interactions with DNA. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3533]

The facile preparation of a racemic hydrazine bridged diphosphonium compound possessing a ring system analogous to bicyclo[3.3.2]decane is reported. Although the reaction yield is low, the structure of the compound, which possesses an eight-membered ring, two phosphonium cationic centers, a biimino bridge, molecular chirality and two fused aromatic rings locked into roughly perpendicular planes is unusual. The compound displays substantial biological activity in the brine shrimp test and cleaves plasmid DNA.

A Zn(II) complex with N-benzyloxycarbonylglycinato ligands was studied by non-isothermal methods, in particular Kissinger–Akahira–Sunose’s method, and further analysis of these results was performed by Vyazovkin’s algorithm and an artificial compensation effect. Density functional theory calculations of thermodynamic quantities were performed, and results obtained by both methods are consistent, thus clarifying the mechanism of this very interesting multi-step degradation.

Two novel cadmium(II) complexes with condensation derivatives of 2-acetylpyridine or 2,6-diacetylpyridine with ethyl hydrazinoacetate hydrochloride were synthesized. X-ray crystal structures of the complexes revealed a bidentate coordination of the 2-acetylpyridine derivative, while the symmetric 2,6-diacetylpyridine derivative was coordinated tridentately. It was found that the oxygen atoms were not coordinated to the cadmium ions, despite the fact that they are the position to form six membered chelate rings. NMR spectroscopy investigations showed that the coordination properties of the ligands do not change in solution. Both complexes possess cytotoxic potential, as determined by the toxicity test to Artemia (C) 2011 Published by Elsevier Ltd.

Organometallic Cd(II) compounds have recently attracted attention for their anticancer activity. The interaction of the dinuclear complex of Cd(II) with the condensation product of 2-acetylpyridine and malonic acid dihydrazide, N',N'(2)-bis[(1E)-1-(2pyridyl) ethylidene] propanedihydrazide (Cd(II)H(2)L), with calf thymus DNA (CT-DNA) was monitored by blue shift in UV-vis spectra of the complex. The binding constant of Cd(II) H2L complex with CT-DNA was determined (K(B) = 1.8 x 10(4) M(-1)) and was indicative of minor groove binding. Agarose gel electrophoretic changes in mobility of supercoiled and circular forms of pBR322 and pUC18 plasmids in the presence of the complex suggest that conformational changes in the plasmids occur upon binding of the Cd(II) H2L complex. The Cd(II) H2L complex induced perturbation of the cell cycle phase distribution and an increase in the percentage of cells in the sub-G1 phase of human cervical cancer HeLa cell line and murine melanoma B16 cell line. Immunoblotting analysis showed the overexpression of Bcl-2 protein with the Cd(II)H(2)L complex. (C) 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 25: 175-182, 2011; View this article online at wileyonlinelibrary.com. DOI 10:1002/jbt.20374

Thermal behavior of Co(II), Cd(II), and Zn(II) complexes with N-benzyloxycarbonylglycinato ligand was investigated using the results of TG, DSC and DTG analysis obtained at different heating rates (2.5 to 30 °C min−1), from room temperature to about 900 °C. Mechanisms of complex degradation, as well as enthalpies of the degradation processes were determined. It is shown that thermal stability of investigated complexes correlates with their crystal structures, especially with the presence of crystallization and coordinated water molecules. The values of dehydration enthalpies are discussed and correlated with composition of the complexes. Kissinger’s, Ozawa’s, and Friedman’s isoconversion methods were used for the determination of kinetic parameters: the pre-exponential factor A and the apparent activation energy E a. For all three complexes and all steps of degradation, the values of kinetics parameters obtained by Kissinger’s and Ozawa’s methods are in good agreement. The results obtained by Friedman’s method showed that some decomposition steps are simple and some others are complex ones.

Condensation derivatives of ethyl hydrazinoacetate with 2-formylpyridine and quinoline-2-carboxaldehyde were synthesized. Pd(II), Pt(II) and Cd(II) complexes with the 2-formylpyridine derivative and a Cd(II) complex with the quinoline-2-carboxaldehyde derivative were synthesized and characterized by spectroscopic techniques. In the complexes, both ligands are coordinated in neutral NN bidentate modes, while the remaining two coordination sites are occupied by chloride. All compounds showed biological activity when tested against Escherichia coli, Bacillus subtilis and Staphylococcus aureus.

In an attempt to synthesize a Cr(III) complex of 2′-[1-(2-pyridinyl)ethylidene]oxamohydrazide an azine product 2-{1-[(1-(2-pyridinio)ethylidene)hydrazono]ethyl}pyridinium diperchlorate was obtained by an electrophilic acyl substitution catalyzed by Cr(III). Its structure was determined by X-ray crystal analysis and showed significant changes in comparison to the corresponding unprotonated compound. The 2-{1-[(1-(2-pyridinio)ethylidene)hydrazono]ethyl}pyridinium diperchlorate crystallizes in the space group P21/n of the monoclinic crystal system with unit cell parameters a = 14.3809(3) A, b = 24.1516(5) A, c = 15.4471(3) A, β = 99.930(2)°, V = 5284.74(19) A3 and Z = 12, i.e. three molecules per asymmetric unit. In the template condensation of the 2′-[1-(2-pyridinyl)ethylidene]oxamohydrazide in presence of the chromium(III) ion the 2-{1-[(1-(2-pyridinio)ethylidene)hydrazono]ethyl}pyridinium diperchlorate was obtained and characterized by NMR spectroscopy and X-ray crystallography.

In this paper the first complexes of M(2+) ions (M(2+) = Zn(2+), Cd(2+) and Co(2+)) with N-benzyloxycarbonyl-S-phenylalaninato ligand (1-3) are described. The new complexes were characterized by means of elemental analysis, IR and UV-vis spectroscopy, molar conductivity measurements and (1)H, (13)C and (15)N NMR spectroscopy (1D and 2D). The Co(II) complex adopts an octahedral geometry, and the Zn(II) and Cd(II) complexes adopt a tetrahedral one. For the first time, the antimicrobial activity of N-benzyloxycarbonyl-S-phenylalaninato ligand (N-Boc-S-phe) and the complexes 1-3 was investigated against Gram-positive: Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Bacillus subtilis and Gram-negative bacteria: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and two strains of the yeast Candida albicans. It was shown that the complexes were effective against most strains. The best activity was detected against the yeast C. albicans. (C) 2008 Elsevier Masson SAS. All rights reserved.

The bimetallic [Ni-2(H(2)L2)(2)](ClO4)(4) (1), [Ni-2(HL2)(H(2)L2)](ClO4)(3) (2) and [Zn-2(H(2)L2)(2)](BF4)(4) (3) complexes (H(2)L2 = N',N'(2)-bis[(1E)-1-(2-pyridyl)ethylidene]propanedihydrazide) were synthesized and characterized. The structure of complexes (1) and (2) was established by X-ray analysis. NMR spectroscopy was used for the characterization of complex (3). The complexes (1) and (2) were obtained from the same synthetic reaction and two crystal types of these complexes have been isolated during the fractional crystallization process. In complex (1) each Ni(II) ion is coordinated with two NNO donor atom sets from two H(2)L2 ligands forming an octahedral geometry. Similarly, in complex (2) the octahedral geometry of each Ni(II) ion is attained by coordination of two NNO donor atom sets, one from the neutral and the other from the monoanionic form of the ligand. The antimicrobial activity of the ligand and complexes is also presented. (C) 2009 Elsevier Ltd. All rights reserved.

Five new complexes of Pt(II), Pd(II), Co(III) and Ni(II) with 2-pyridine(quinoline) carboxaldehyde selenose-micarbazones were synthesized and characterized. Crystal structures of Pt(II) complex with the pyridine derivative and Co(III) complex with the quinoline derivative were determined. In all complexes the ligands were coordinated through N(2)Se donor atom set forming either square-planar (Pt, Pd) or octahedral (Co, Ni) geometry. All complexes showed biological activity. (C) 2009 Elsevier B. V. All rights reserved.

A new dinuclear complex of Cd(II) with N',N'(2)-bis[(1E)-1-(2-pyridyl)ethylidene]propanedihydrazide (H2L) was synthesized and its crystal structure determined. The basic structural unit of the complex is the binuclear [Cd-2(H2O)(2)(H2L)(2)](4+) cation, where each cadmium atom is heptacoordinated by two tridentate H2L ligands, by means of the NNO chelating system, and one water molecule. A 12-membered macrocycle is defined at the core of the binuclear cation. The complex showed a pronounced cytotoxic activity to murine melanoma B16 cells and human cervical cancer HeLa cells. (c) 2007 Elsevier B.V. All rights reserved.

Complexes of zinc and iron with N', N'(2)- bis[(1E)-1-(2-pyridyl) ethylidene] ethanedihydrazide (H(2)L1) and N', N'(2)-bis[( 1E)-1-(2-pyridyl) ethylidene] propanedihydrazide (H(2)L2) were prepared. Zn-II complexes with both ligands have an octahedral geometry. In the complex of Zn-II with H(2)L1, the ligand is coordinated as a tridentate species in the monoanionic form, building two five-membered rings around Zn-II. Three remaining coordination sites are occupied by water molecules, and in the outer sphere there is a ClO4- ion. In the other Zn-II complex, the H(2)L2 ligand is coordinated in the enol form as a tetradenate species, forming a five-memebered, a six-membered and a seven-membered ring, the remaining coordination sites being occupied by water molecules, while in the outer sphere there are two ClO4- ions. The Fe-III complex with H(2)L2 is a high-spin octahedral complex. The ligand is coordinated in the enol form, in a tetradentate fashion via pyridine and hydrazone nitrogens. The remaining two coordination sites in the complex are occupied by water molecules and a Cl) ion, and in the outer sphere there are two Cl) anions. The octahedral Fe-III complex obtained from the reaction of FeCl(3)center dot 6H(2)O and H(2)L1 in absolute ethanol has the formula [Fe(HL1) Cl-2(H(2)0)] center dot 1.5H(2)O. However, during coordination of the H(2)L1 ligand to Fe-III in water, oxidative degradation of the side chain ( - CO - CO -) and reduction of Fe-III to Fe-II occurs, affording octahedral tris(1-(2-pyridyl) ethylidenehydrazine] iron(II) perchlorate, as confirmed by X-ray structure analysis.

The complex [Co(H 2 L)(H 2 O)(MeOH)](ClO 4 ) 2 [H 2 L] = 2′,2‴-(2,6-pyridindiyl-diethylidene)-dioxamohydrazide] has been prepared by direct and template syntheses and characterized by elemental analysis, IR spectroscopy, and magnetic susceptibility measurements. The crystal structure of the complex has also been determined. The cobalt atom is seven coordinated with approximately pentagonal-bipyramidal geometry. The H 2 O and methanol are axial with the planar pentadentate H 2 L ligand forming the equatorial plane. The possible reaction mechanism has been proposed.