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We have synthesized and characterized Co(II) (1), Zn(II) (2), Fe(III) (3) and Cu(II) (4) complexes of 2,2'‐[2,6‐pyridinediylbis(ethylidyne‐1‐hydrazinyl‐2‐ylidene)]bis[N,N,N‐trimethyl‐2‐oxoethanaminium] dichloride (H2LCl2) by NMR, IR, and X‐Band EPR spectroscopy, respectively, as well as by single‐crystal X‐ray structural analysis. H2LCl2 belongs to the class of diacetylpyridine bis(hydrazone) ligands and bears two positively charged quaternary ammonium functionalities. The complexes 1–3 possess a pentagonal‐bipyramidal geometry, whereas 4 has square‐pyramidal geometry. Redox reactivity and SOD activity of the complexes was studied by means of electrochemical measurements in aqueous‐buffer and DMF or DMSO solutions, respectively, as well as by stopped‐flow measurements. Complexes 1–3 do not have SOD activity, whereas 4 exhibits a high catalytic rate constant for the superoxide dismutation, kcat = 1.73 × 107 m–1 s–1 (in MOPS buffer solution of pH = 7.4). The results were discussed in terms of complex redox potentials, electrostatic interactions and their spatial distribution, kinetic lability of metal centers, and stability of peroxo intermediates, respectively.

Two Co(III) complexes with condensation product of thiosemicarbazide and 2-acetylthiazole (HL1 ligand, (E)-2-(1-(thiazol-2-yl)ethylidene)hydrazine-1-carbothioamide) and the condensation product of 2-acetylpyridine and Girard's P reagent (HL2Cl ligand, (E)-1-(2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethyl)pyridin-1-ium chloride) have been synthesized and characterized based on the results of single-crystal X-ray diffraction, NMR and IR spectroscopy and elemental analysis. Cobalt(III) complex with HL1 ligand, [Co(L1)2]BF4⋅H2O (1), is bis octahedral complex in which two deprotonated ligand molecules coordinate in a mer arrangement through two NNS sets of donor atoms. In cobalt(III) complex with HL2Cl, [Co(L2)(N3)3] (2), the ligand is coordinated in deprotonated, formally neutral, form to Co(III) ion in tridentate fashion through NNO set of donor atoms, and the other three coordination sites of a monokis octahedron are occupied by meridionally coordinated azide anions. DFT calculations were performed to elucidate coordination preferences of these ligands toward Co(III) ion. This is an accepted version of the manuscript: Darmanović, D., Radanović, D., Jevtović, M., Turel, I., Pevec, A., Milčić, M., Gruden, M., Zlatar, M., Đorđević, N., Anđelković, K.,& Čobeljić, B.. (2022) "Coordination preferences of NNO and NNS Schiff base ligands with Co(III) complexes: Synthesis, characterization and DFT calculation," Journal of Molecular Structure Elsevier., 133509. doi: [https://doi.org/10.1016/j.molstruc.2022.133509] Supplementary material: [https://cer.ihtm.bg.ac.rs/handle/123456789/5112] Crystallographic data (CCDC 2168741): [https://cer.ihtm.bg.ac.rs/handle/123456789/5110] Crystallographic data (CCDC 2168742): [https://cer.ihtm.bg.ac.rs/handle/123456789/5111] Published version: [https://cer.ihtm.bg.ac.rs/handle/123456789/5113]

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]

Binuclear double end-on azido bridged Ni(II) complex (1) with composition [Ni2L2(?-1,1-N3)2(N3)2]?6H2O, (L = (E)-N,N,N-trimethyl-2-oxo-2-(2- -(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-amin) was synthesized and characterized by single-crystal X-ray diffraction method. Ni(II) ions are hexacoordinated with the tridentate heteroaromatic hydrazone-based ligand and three azido ligands (one terminal and two are end-on bridges). DFT calculations revealed that coupling between two Ni(II) centers is ferromagnetic in agreement with binuclear Ni(II) complexes with similar structures.

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]

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]

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]

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]

A series of Na+, K+ and Ca2+ salts of chromium(III) complexes with the hexadentate (±)-1,3-pentanediamine-N,N,N′,N′-tetraacetate (1,3-pndta) ligand was evaluated. The extent of distortion exhibited in the geometry of these octahedral complexes was computed and related to the configuration at the metal center and the ligand stereogenic center. The materials have been used to investigate the effect of the counter ion and the diamine ring substitution on the self organization and degree of hydration of these molecules in crystals. Various modes of carboxylate binding to metal atoms have been related to the formation of 3D, 2D and 1D polymeric structures. The electronic absorption and 1H NMR spectra of 1,3-pndta-Cr(III) complexes are discussed in relation to those of 1,3-pdta-Cr(III) complex (1,3-propanediamine-N,N,N′,N′-tetraacetate ion) of known structure.

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.

This paper reports the synthesis and X-ray characteristics of the missing homonuclear s-block metal complex {[Sr-2(1,3-pdta)(H2O)(6)]center dot H2O}(n). In the title compound, the hexadentate 1,3-propanediaminetetraacetate (1,3-pdta) ligand joins to two Sr(II) centers via the diamine chain. Moreover, each Sr(II) is bridged through two carboxylate O atoms and a water molecule to two neighboring Sr(II) ions. The coordination sphere around each Sr(II) ion consists of one diamine nitrogen, four carboxylate oxygens and four water molecules. Comparison with the previously reported M(II)-1,3-pdta complexes reveals that increasing of the ion size results in the incorporation of water molecules into its first coordination sphere and consequent increase of the coordination number (C.N.) from six to seven or eight, while keeping the hexadentate coordination mode of the ligand. Further increase of the metal ion size leads to the loss of the chelating properties of the diamine and formation of a bis-tridentate complex. Associated with it is the change in the binding mode of the carboxylate groups. This forms the basis for classification of divalent metal 1,3-pdta complexes into five distinct structural classes. Additionally, in the present study X-ray powder diffraction and IR spectroscopy were used to distinguish the different structural types of M(II)-1,3-pdta complexes, including Ba[Ba(1,3-pdta)]center dot 2H(2)O which has been used for their preparation.

Two novel Cd(II) and Zn(II) complexes with the condensation product of 2-formylpyridine and selenosemicarbazide were synthesized. The structure of Cd(II) complex was determined by X-ray crystallography. The ligand is coordinated in a neutral form via pyridine and azomethine nitrogen atoms and the selenium donor. The cadmium ion completes its five-coordination by two chloride ligands, forming a square-pyramidal geometry. The structure of Zn(II) complex was established by analysis of spectroscopic data, which indicated coordination of the ligand as a bidentate via the selenium and the azomethine nitrogen atoms. The cytotoxic activity of the newly synthesized complexes, as well as if five structurally related complexes and the ligand evaluated against eight tumor cell lines. The new Cd(II) complex showed the highest activity similar to cisplatin with IC50 less than 10muM for all cell lines. Cell cycle distribution and apoptosis study showed that Cd(II) complex and cisplatin might have some similarity in anticancer activity, which was not the case for cisplatin and other studied complexes. Effects of the complexes on matrix metalloproteinases (MMPs) MMP-9 and MMP-2 was also studied. Cd(II) and Zn(II) complexes and cisplatin increased MMP-2 activity in supernatants of tested cells, while Ni(II) complex with the same ligand decreased the activity, implying a possible activity in preventing tumor invasion and metastasis processes.

The mononuclear chromium(III) complex containing quadridentate ligand ethylenediamine-N,N'-diacetate (edda) and the corresponding dinuclear complex bridged by pyrazole-3,5-dicarboxylate (pzdc) are investigated by molecular mechanics calculations. Conformational analysis has been performed using the consistent force field (CFF) method, with the parameters developed previously for edta-type complexes and supplemented with new parameters for dinuclear system. These calculations indicated that many properties of [Cr-2(edda)(2)(mu-pzdc)](-) system can be explained by steric effects. Density functional theory (DFT) was applied to describe the magnetic couplings in [Cr-2(edda)(2)(mu-pzdc)](-). (c) 2008 Elsevier B.V. All rights reserved.

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]

The trans(O6) isomer of the Ba[Co(1,3-pddadp)] · 8H2O complex (where 1,3-pddadp represents hexadentate 1,3-propanediamine-N,N′-diacetate-N,N′-di-3-propionate ion) has been prepared and characterized by X-ray crystallography. In the crystal structure the complex cations and anions are bridged by carboxylate oxygen atoms from the in-plane coordinated glycinate rings (G-rings) of [Co(1,3-pddadp)]2− and by the barium-coordinated water molecules, thus forming 1D polymeric chains, separated by infinite water tapes hydrogen bonded to the [Co(1,3-pddadp)]2− carboxylate oxygens from the out-of-plane β-alaninate rings (R-rings). Conformational analysis of the three possible geometrical isomers: trans(O5), trans(O5O6), and trans(O6) of the [Co(1,3-pddadp)]2− complex, with ligand acting as hexadentate, as well as of the corresponding complexes of Ni(II) and Cr(III) has been performed using the consistent force field (CFF) method, with the parameters developed previously for edta-type complexes of chromium(III) and supplemented with new parameters for cobalt(II) and nickel(II). The energy-minimized structure of the trans(O5O6) isomer represents the global minimum for the [M(1,3-pddadp)]n− (M = Co(II), Ni(II), and Cr(III)) species. The occurrence of the least energetically favored trans(O6) isomer in a crystal and the exceptional conformation of the axially oriented β-alaninate rings can be accounted for by the stabilizing role of the infinite tapes of planar cyclic water pentamers and hexamers which act as a “glue” to reinforce the coordination polymeric chains.

The ability of Mn(II) ion to form two distinctly different complexes with 1,3-propanediaminetetraacetate (1,3-pdta) ligand has been demonstrated by performing X-ray analyses of their crystalline Mg(II) salts. The two types of Mn(II) complexes have been obtained by different synthetic routes and their crystals constitute, respectively, the solid solution of the composition [Mg(H2O)6][Mg0.5Mn0.5(1,3-pdta)] · 2H2O (1) and the ordered crystals of the composition [Mg(H2O)6][Mn(1,3-pdta)(H2O)] · 2H2O (2). In both, six- 1 and seven-coordinated 2 Mn(II) complexes the 1,3-pdta ligand acts as a hexadentate. As 2 makes the second example of the seven-coordinated 1,3-pdta complex with divalent transition metal ion, the other being the [Mg(H2O)6][Cd(1,3-pdta)(H2O)] · 2H2O (3) complex, the paper reports the results of X-ray investigations of both of these complexes at 130 K.

A novel binuclear Co(II) complex, [Co-2(Cl)(2)tpmc](BF4)(2) (tpmc=N,N,N",N"'-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane), was prepared and structurally characterized by X-ray diffraction analysis at low temperature. The complex crystallizes in P2(1)/c space group of the monoclinic crystal system, and its crystals are isomorphic with those Of [Cu-2(Br)(2)tpmc](ClO4)(2) complex. In the crystal structure the complex cations [Co-2(Cl)(2)tpmc](2+) are settled around the inversion centres. Cobalt(II) is exo coordinated with four macrocyclic N atoms, and Cl- supplements the fifth coordination site. Based on the index of trigonality, the coordination polyhedron formed around Co(II) ion is described as distorted trigonal bipyramid. Two metal centres are at a distance of 5.710 angstrom. This is the first Co(II) complex for which X-ray analysis confirmed a chair conformation of tpmc ligand. IR, EPR (X-band) and UV/VIS absorption and reflectance spectra, molar conductivities and magnetic measurements (SQUID) are used to study the investigated complex. A comparative structural analysis with some of the described Co(II) and Cu(II) complexes of analogous geometries and type of pendant azamacrocyclic ligands was also done.

Three new hexadentate complexes: [Mg(H2O)6][Zn(1,3-pdta)] · 2H2O (1), [Zn(H2O)6][Zn(1,3-pdta)] · 2H2O (2) and [Mg(H2O)6][Cd(1,3-pdta)(H2O)] · 2H2O (3) (where 1,3-pdta represents the 1,3-propanediaminetetraacetate ion) have been synthesized and characterized. The structures of 1, 2 and 3 have been determined by X-ray crystallography. The complexes 1 and 2 crystallize in the space group Pnna of the orthorhombic crystal system and their crystals are isomorphic with those of other 1,3-pdta complexes containing metal(II) ions of the ionic radii of about 0.8–0.9 A. The complex 3 crystallizes in the space group Pbcn of the orthorhombic crystal system and its crystals are isomorphic with those of [Mg(H2O)6][Mn(edta)(H2O)] · 2H2O (where edta is the ethylenediaminetetraacetate ion). The structural units of 1 and 2 consist of discrete [Zn(1,3-pdta)]2− and [MII(H2O)6]2+ (M(II) = Mg (1) or Zn (2)) octahedra, and two water solvent molecules all of which lie on a twofold axis of symmetry. The structural unit of 3 consists of discrete complex ions: [Cd(1,3-pdta)(H2O)]2− and [Mg(H2O)6]2+ which are situated on twofold axis of symmetry and inversion centre, respectively, and two symmetry related water solvent molecules. The coordination polyhedron formed around Cd(II) is distorted pentagonal bipyramid. In contrast to crystals 1 and 2 in which the complex cations and anions alternate, each being octahedrally surrounded by the counter ions, a layered arrangement of cationic and anionic species is observed in 3.

The hexadentate trans(O5O6)-K[Co(1,3-pddadp)] · 3H2O complex (where 1,3-pddadp represents the 1,3-propanediamine-N,N′-diacetate-N,N′-di-3-propionate ion) has been characterized by single-crystal X-ray crystallography. The complex crystallizes in the P2/c space group of the monoclinic crystal system. In the crystal structure of trans(O5O6)-K[Co(1,3-pddadp)] · 3H2O the potassium ions and two solvent water molecules (O1W and O3W) are settled on a twofold axis of symmetry. The octahedral complex units trans(O5O6)-[Co(1,3-pddadp)]− are bridged by carboxylate oxygen atoms with the potassium ions to build a two-dimensional polymer structure, separated by layers formed by hydrogen bonded water molecules and carboxylate oxygens. The coordination polyhedra around K1 and K2 are found to be distorted square antiprism and twisted bi-capped trigonal prism, respectively. Conformational analysis of the three possible geometrical isomers (trans(O5), trans(O5O6) and trans(O6)) of the [Co(1,3-pddadp)]− complex, was performed using the Consistent Force Field (CFF) program, with the parameters developed previously for edta-type complexes and new parameters for Co(III). Molecular mechanics (MM) calculations reproduced very well the crystallographically characterized structures (trans(O5O6)-[Co(1,3-pddadp)]− and trans(O6)-[Co(1,3-pddadp)]−).

Starting from Ba2(1,3-pddadp)·8H2O (1,3-pddadp=1,3-propanediamine-N,N′-diacetate-N,N′-di-3-propionate ion) and CoSO4, a new hexadentate [CoII(1,3-pddadp)]2− complex has been prepared. The trans(O6) geometry of this complex was confirmed by comparison of its i.r. and u.v.–vis. spectra with those of [CoII(1,3-pdta)]2− (1,3-pdta is the 1,3-propanediaminetetraacetate ion) and trans(O6)-[CoIII(1,3-pddadp)]− complexes of known X-ray crystal structure. Magnetic and electrolytic conductivity properties of these complexes have also been discussed.

Starting from Ba[Ba(1,3-pdta)] · 2H2O (where 1,3-pdta is the 1,3-propanediaminetetraacetate ion) two new hexadentate complexes: [Mg(H2O)6][Mg(1,3-pdta)] · 2H2O (1) and [Ca(H2O)3Ca(1,3-pdta)(H2O)] · 2H2O (2) have been prepared and characterized. The complexes differ in coordination numbers and geometry, and in coordinative bond distances. They also display dramatically different packing patterns: while the structural units of (1) consist of discrete [Mg(1,3-pdta)]2− and [Mg(H2O)6]2+ octahedra arranged in the solid-state in a close packed fashion, the crystals of (2) are composed of one-dimensional chains of ligand-bridged coordination complexes, such that no discrete complex units exist. The calcium(II) ion (Ca1), coordinated with the 1,3-pdta ligand and two symmetry-related water molecules, forms an irregular square-antiprismatic structure, which is not common for the M-1,3-pdta system. The coordination polyhedron formed around the counter ion (Ca2) can best be described as a dodecahedron. Six-membered diamine chelate rings in complexes (1) and (2) are found to be in twist-boat and distorted chair conformations, respectively. Infrared and solid-state 13C NMR spectra of Ba-, Mg- and Ca-1,3-pdta complexes have also been presented.

The pentadentate complex cis-polar,trans(Cl,O5)-Na2[Rh(1,3-pddadp)Cl] · 7H2O (where 1,3-pddadp is the 1,3-propanediamine-N,N′-diacetate-N,N′-di-3-propionate ion) was prepared and characterized. The structure of the complex was determined by X-ray analysis. The rhodium(III) ion is surrounded octahedrally by the two N and three O atoms of the 1,3-pddadp ligand and one chloride anion. The chloride anion occupies the trans position with respect to the oxygen atom of the axial glycinate ring and the cis-polar orientation with respect to the tertiary nitrogen atom bonded to the uncoordinated 3-propionate group. The investigated pentadentate complex derives directly from the trans(O5O6) isomer of the corresponding hexadentate [Rh(1,3-pddadp)]− complex. The conformations of the chelate rings were found to be envelope and flat for in-plane (G′′) and axial (R′) glycinate rings, and sofa and chair for in-plane β-alaninate (G′) and 1,3-propanediamine (T) rings, respectively. The electronic absorption spectrum of cis-polar,trans(Cl,O5)-[Rh(1,3-pddadp)Cl]2 − is also given and compared with those of hexadentate trans(O5O6)-[Rh(1,3-pddadp)]− and trans(O5)-[Rh(1,3-pddadp)]− complexes.

Starting from Ba[Ba(1,3-pdta)]·2H2O three new hexadentate cobalt(II) complexes [MII(H2O)6][CoII(1,3-pdta)]·2H2O (MII=Ba (1), Co (2) and Mg (3)) (where 1,3-pdta represents the 1,3-propanediaminetetraacetate ion) have been prepared and characterized. Presented in this paper, the crystal structures of the complexes containing CoII and MgII counter cations are isomorphic, as are the other crystal structures of metal(II) complexes with 1,3-pdta ligand, so far reported in the literature. The complexes crystallize in the space group Pnna of the orthorhombic crystal system. The structural unit consists of discrete [CoII(1,3-pdta)]2− and [MII(H2O)6]2+ octahedra, and two water solvent molecules all of which lie on a twofold axis of symmetry. The complex cations and anions alternate in the crystal lattice each being octahedrally surrounded by the counter ions. Electronic absorption spectra of [CoII(1,3-pdta)]2− complexes are presented and discussed in terms of octahedral distortion in edta-type CoII complexes.

Structural data are given for two earlier reported hexadentate Rh(III) complexes: trans -(O 5 )-Na[Rh(1,3-pddadp)]·H 2 O ( 1 ) and trans -(O 5 O 6 )-Na[Rh(1,3-pddadp)]·3H 2 O ( 2 ) (1,3-pddadp=1,3-propanediamine- N , N ′-diacetate- N , N ′-di-3-propionate ion) . Both complexes have been resolved. The absolute configuration around the Rh(III) ion for the (+) 589 optical isomer in the crystal 2 has been determined to be the Λ (ΛΔΛ). The complexes crystallize in monoclinic P 2 1 / c ( 1 ) and orthorhombic P 2 1 2 1 2 1 ( 2 ) space groups. Based on a low-temperature measurements (150 K), both crystal structures have been refined to a final R value of 0.029. The conformations of the glycinate rings in 2 are common (R relatively flat and G with a significant deviation) while the two R rings of 1 (in an envelope and twist conformations) show unusually large total deviation (of −6°av.). The six-membered β-alaninate (R, G) and the diamine (T) rings adopt in both compounds distorted boat ( twist - boat ) conformations. Octahedral distortion of [Rh(edta-type)] − chelates is discussed in relation to the structure of the ligand and the geometry of the complex. The CD spectra of the Λ-(−) 589 - trans -(O 5 )-Rh[(1,3-pddadp)] − ( 1 ) and Λ-(+) 589 - trans -(O 5 O 6 )-[Rh(1,3-pddadp)] − ( 2 ) and the other Λ-[Rh(edta-type)] − complexes have been correlated and discussed. The lowest energy CD component is positive for the Λ-isomers of 1 and 2 , but negative for the other Λ-[Rh(edta-type)] − complexes that is forced to reverse the assignments of the CD peaks.

Two square-pyramidal complexes, Mg[Cu(edtp)]·10H2O (1) (edtp=ethylenediamine-N,N,N′,N′-tetra-3-propionate ion, acting as a pentadentate) and Mg[Cu(ed3p)]2·6H2O (2) (ed3p=ethylenediamine-N,N,N′-tri-3-propionate ion) have been prepared and characterized. A square-pyramidal geometry was established crystallographically for the complex Mg[Cu(edtp)]·10H2O (1). The Cu(II) ion in the complex anion is displaced by 0.195 A from the plane of the four in-plane (2N and 2O) ligand atoms towards the apical oxygen atom of the β-alaninate (R) ring (CuOax=2.173 A). The conformations of the chelate rings are those usually expected for these kinds of chelates (a five-membered diamine (E) ring in a twist(λ) conformation, two β-alaninate (G1 and G2) rings in a distorted twist-chair and one β-alaninate (R) ring in a distorted twist-boat conformation). The structural data correlating the square-pyramidal stereochemistry are discussed with reference to those obtained for related complexes. Electronic absorption and reflectance spectra are discussed in comparison with those of related complexes of known structures. IR data (carboxylate region) are also reported.

The hexadentate complex trans(O5)-Mg[Cu(ed3ap)]·8H2O (1) (ed3ap = ethylenediamine-N,N,N′-triacetate-N′-3-propionate (4-) ion) has been prepared and its structure established by X-ray crystallography. The complex crystallizes in space group Pna21 of the orthorhombic crystal system. The structure converged to R = 0.076 for 2213 observed reflections. The Cu(II) ion is surrounded by two nitrogen and four oxygen atoms of the ligand, making an elongated rhombic octahedron (tetragonality, T = 0.859). The conformations of the chelate rings of the complex anion were found to be an envelope (or twist) for the five-membered rings and a distorted skew-boat (half-chair) for the G2 β-alaninate ring. The extremely large total deviation observed for the R2 ring (-11°) is not common for axially coordinated glycinates in M-edta-type complexes. A comparison of the structures of octahedral Cu(II)-edta-type complexes shows an expected variation in their stereochemistry, depending on the structure of the ligand and the geometr...

The hexadentate complex Mg[Cu(1,3-pdta)]·8H2O (1) (where 1,3-pdta represents the 1,3-propanediaminetetraacetate ion) has been prepared and isolated and its structure established by X-ray crystallography. The structure converged to R=0.030 for 1537 observed reflections. The Cu(II) ion is surrounded by two nitrogen atoms and four oxygen atoms of the ligand, making a tetragonally elongated octahedron (T=0.868). The Mg cation is bonded octahedrally to six water molecules. Both complex ions utilize a two-fold symmetry axis that is present in the crystal. The conformations of the chelate rings were found to be envelope for the glycinates and skew-boat for the six-membered diamine (T) ring. Comparison of the structures of the hexadentate copper(II)–edta-type complexes shows an expected variation in their stereochemistry, depending on the structure of the ligand. Infrared (carboxylate region) and electronic absorption spectra are also given.

Three square-pyramidal copper(II) complexes containing a linear O-N-N-O-type tetradentate ligand have been prepared and characterized. The ligands used are 1,3-propanediamine-N,N′-diacetate ion (1,3-pdda), ethylenediamine-N,N′-di-3-propionate ion (eddp) and 1,3-propanediamine-N,N′-di-3-propionate ion (1,3-pddp). In the three compounds a water molecule is in the axial position while the four atoms of ligand are in the basal plane. A five-coordinate, square-pyramidal geometry has been established crystallographically for the complexes [Cu(1,3-pdda)(H2O)] (1) (orthorhombic, Pnma, a = 8.937(4), b = 11.770(5), c = 10.269(5) A, V = 1080.2(8) A3, Z = 4 and R = 0.0699) and [Cu(eddp)(H2O)]·3.5H2O (2) (monoclinic, C2/c, a = 24.430(8), b = 12.195(3), c = 10.514(2) A, β = 110.92(2) V = 2926(1) A3, Z = 8 and R = 0.0515). The Cu(II) ions of these structures are lifted out of plane of the four in-plane ligand atoms by distances ϱ = 0.182(5) and 0.154(1) A, respectively. The six-membered diamine ring of complex 1 assumes the stable chair conformation. The other rings of chelates have expected conformations. The structural data correlating the square-pyramidal stereochemistry are discussed in relation to those obtained for similar complexes. The IR and electronic absorption spectra of [Cu(edda-type)(H2O)] complexes are discussed in comparison with those of related complexes of known geometries. The magnetic measurements are also reported for the complexes studied.

Three new 1D coordination polymers, [Pb-2(CH3SO3)(4)(H2O)(2)](n), [Hg(CH3SO3)(2)(H2O)(2)](n) and [Sr(CH3SO3)(2)(H2O)](n), were synthesized as large single crystals. The crystals were analyzed and characterized by the means of X-ray analysis, IR and NMR spectroscopy, elemental analysis and solid state UV-Vis spectroscopy. The formation of 1D polymeric chains in the crystal structures of the title compounds is affected by the various bonding modes of the bridging methanesulfonate groups. The studied compounds showed no decomposition in the air. This is the peer-reviewed version of the article: M. Đorđević, D. Jeremić, G.N. Kaluđerović, S. Gómez-Ruiz, B. Anđelković, D. Radanović, I. Brčeski, Synthesis and spectroscopic properties of large single-crystals of Pb(II), Hg(II) and Sr(II) methanesulfonato 1D coordination polymers, Polyhedron (2014), doi: [http://dx.doi.org/10.1016/j.poly.2014.05.056] [http://cer.ihtm.bg.ac.rs/handle/123456789/1429]

The octahedral copper(II) complexes of 1,3-propanediamine-N,N′-diacetic-N,N′-di-3-propionic acid (H41,3-pddadp) prepared in the region of pH 2 to 7 are hexadentates. Only one (trans(O6)) of the three geometrical isomers was found to dominate. The trans(O6)-Na2[Cu(1,3-pddadp)]·NaNO3·2H2O complex crystallizes in the space group P2/c of the monoclinic crystal system with a=9.231(2), b=11.736(14), c=10.150(2) A, β=109.33(2)° and Z=2. The conformations of the chelate rings are found to be envelope for the glycinate and skew-boat for the β-alaninate and 1,3-propanediamine rings. The complex is a tetragonally elongated octahedron (T ∼0.8) with C2 molecular symmetry. IR (carboxylate region) and electronic absorption spectra are assigned and discussed in relation to the structure of complexes. For hexadentate Cu(II) edta-type complexes of known structures the strain analysis is also discussed.

Structural variations modulated by ethyl side group have been analyzed for nickel(II) and copper(II) complexes with (+/-)-1,3-pentanediamine-N,N,N',N'-tetraacetate ligand (1,3-pndta) and its pentadentate derivative (+/-)-1,3-pentanediamine-N,N,N'-triacetate (1,3-pnd3a). X-ray results obtained for the octahedral 1,3-pndta-Ni(II) complex indicate the distinct correlation of the central chirality of the metal with the chirality at the diamine alpha-carbon, which leads to the formation of a racemic mixture of Delta Lambda Delta(R) and Lambda Delta Lambda(S) enantiomeric anionic complexes, where the R and S labels designate the absolute configuration at the ligand (ethyl-substituted) stereogenic center. These stereoisomers are those required to maintain an equatorial ethyl group on the central six-membered chelate ring, whose conformation is lambda twist-boat for the Delta Lambda Delta isomer and 8 twist-boat for the Lambda Delta Lambda isomer. Ethyl group discernibly affects the variation of the Ni-N and Ni-O bond lengths compared to the analogous complex lacking the substitution of one of the diastereotopic diamine CH2 hydrogens and functions as steric bulkiness which hampers an efficient and of high symmetry packing, observed in the crystals of the parent complex. The infrared and electronic absorption spectra of hexadentate Mg[Ni(1,3-pndta)]center dot 10H(2)O (1) and Mg[Cu(1,3-pndta)]center dot 7H(2)O (3), and pentadentate Mg[Ni-2(1,3-pnd3a)(2)]center dot 8H(2)O (2) and MgiCu2(1,3-pnd3a)(2)]center dot 7H(2)O (4) complexes are presented and discussed in comparison with those of the analogous Mg[Ni(1,3-pdta)center dot 8H(2)O (5), Ma[Cu(1,3-pdta)]center dot 8H(2)O (6) and Mg[Cu-2(1,3-pd3a)(2)]center dot 7H(2)O (7) complexes of known crystal structures.

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.

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.

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.