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The condensation product of 7-acetyl-6-azaindole and Girard's T reagent ((E)-2-(2-(1-(1H-pyrrolo[2,3-c]pyridin-7-yl)ethylidene)hydrazineyl)-N,N,N-trimethyl-2-oxoethan-1-aminium, HL ligand) was used as a ligand in the reaction with Cu(BF4)2·6H2O and NaN3. The reaction led to the formation of a binuclear Cu(II) complex containing two end-to-end (di-m-1,3-N3) azide bridges, as well as two NNO-donor hydrazone ligands, forming an axially elongated square pyramidal geometry around each Cu(II) center. This end-to-end (di-m-1,3-N3) azide bridge binding mode has not yet occurred in Cu(II) complexes containing the NNO-donor hydrazone ligands, which makes the structure of the complex even more interesting for further studies. The complex was characterized by elemental analysis, IR spectroscopy and X-ray crystallography, and it was found that it crystallizes in the triclinic space group P–1 with the asymmetric unit comprising one Cu(II) centre, zwitterionic ligand L, one azide (N3−) ligand, and BF4− counter anion. Examination of antimicrobial activity of the complex shows higher antifungal and antibacterial activity towards tested Gram-positive bacteria in comparison to the hydrazone ligand, with the antifungal activity of the complex even being comparable to the activity of amphotericin B.

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.

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.

Epinefrin je kateholamin sa značajnom fiziološkom ulogom. Konformacija ovog molekulautiče na njegovu interakciju sa drugim molekulima i na njegove biološke efekte. Na fiziološkimpH vrednostima, koordinativne sposobnosti epinefrina prema gvožđu i redoks interakcije epinefrinasa gvožđem su od suštinske važnosti za razumevanje dve veoma različite pojave. Prva pojava ještetno dejstvo koje hronični psihološki/sredinski stres izaziva na nivou kardiovaskularnog sistema.Druga pojava je umrežavanje kateholaminima bogatih biopolimera i struktura. Kako bi se rasvetlileuloge rastvarača i vodoničnih veza u interakcijama epinefrina sa gvožđem, proučavana jekonformacija epinefrina u vodi i polarnom rastvaraču dimetil sulfoksidu (DMSO).U ovoj disertaciji su predstavljeni rezultati proučavanja mehanizama interakcije epinefrinasa Fe2+ i Fe3+ jonima pri različitim koncentracionim odnosima na pH 7,4, odnosno na pH vrednostikoja odgovara fiziološkim uslovima. U svrhu istraživanja bioloških efekata epinefrina, u ovojdisertaciji su predstavljena ispitivanja efekta Epi-Fe3+ kompleksa na ćelije koje konstitutivnoeksprimiraju adrenergičke receptore.Konformacije epinefrina u polarnim rastvaračima, vodi i DMSO, su proučavane metodamaH nuklearne magnetne rezonance (1H NMR) kao i dvodimenzionalnim metodama nuklearnemagnetne rezonance, i to: 1H - 1H COSY, 1H - 15N HSQC i NOESY. Na NH2 i CH2 grupamaepinefrina su uočeni hemijski neekvivalentni protoni prilikom korišćenja DMSO kao rastvarača.Ove pojave nisu uočene kada je rastvarač bila voda. Analizom uticaja korišćenog rastvarača naNMR spektar, i analizom uticaja povećanja temperature uzorka na NMR spektar, dolazi se dozaključka da jedan od protona amino grupe formira jaku intramolekulsku vezu sa alifatičnomhidroksilnom grupom, koja je pak H donor drugoj intermolekularnoj vezi sa DMSO. PomoćuNOESY metode su prikupljeni podaci o prostornoj poziciji protona u bočnom lancu. Na taj način jeformiran 3D model konformacije epinefrina u DMSO. Ukratko, epin, Epinephrine (Epi) is a catecholamine with important physiological roles. Interactions withother molecules and associated biological effects of Epi are controlled by its molecularconformation. Coordinate interactions of epinephrine with iron at physiological pH and their redoxactivity are crucial for understanding two distinct phenomena. First, the adverse effects that chronicstress causes to cardiovascular system. Second, the cross-linking of biopolymers and frameworkswhich are rich in catecholamines. Conformation of epinephrine in polar solvents, namely indimethyl sulfoxide (DMSO) and water, was investigated in order to shed light on effects solventsand hydrogen bonds exert on interactions of epinephrine with iron.Mechanism of epinephrine interactions with Fe2+ and Fe3+ ions was studied at differentconcentration ratios, at physiological pH (pH 7.4), and the results are presented in this dissertation.For the sake of exploration of biological effects of epinephrine, this dissertation also contains theresults of examination of effects Epi-Fe3+ complex has on cell culture with constitutive expressionof adrenergic receptors.Conformation of epinephrine in polar solvents, namely in dimethyl sulfoxide (DMSO) andwater, was investigated using 1H NMR, 1H - 1H COSY, NOESY and 1H - 15N HSQC methods.When DMSO was used as a solvent, chemical and magnetic nonequivalence of protons was spottedat NH2 and CH2 groups on epinephrine. Characteristics of hydrogen bonds in DMSO weredetermined by studying effect which temperature rise has on NMR spectra and also analyzinginfluences of solvent substitution on NMR spectra. Results have shown that epinephrine inducesstrong intramolecular bond between one of the protons of NH2 group and the OH group on the sidechain. On the other hand, the OH group on the side chain, i.e. the aliphatic OH group, presents aproton donor for intermolecular bond between epinephrine and DMSO. This phenomenon was notnoticed when water was used as a solvent. 3D model

This work is the first report of a very simple and fast one-pot synthesis of nickel oxide (NiO) and hematite (α-Fe2O3) nanoparticles by thermal decomposition of transition metal aqua complexes with camphor sulfonate anions. Obtained nanopowders were characterized by X-ray powder diffraction, Fourier transform IR analysis, scanning electron microscopy, and Energy-dispersive X-ray spectroscopy. X-ray powder diffraction confirmed the formation of high purity NiO and α-Fe2O3 crystal phases. In the case of α-Fe2O3, about five times larger average crystallite size was obtained. Fourier transform IR spectra of synthesized materials showed characteristic peaks for NiO and α-Fe2O3 nanostructures. To visualize the morphology and the chemical composition of the final products Scanning electron microscopy and Energy-dispersive X-ray spectroscopy were performed. The thermogravimetric analysis was done for a better understanding of the general thermal behavior of precursor compounds. This easy-to-perform and fast preparation method opens a broad range of obtained materials’ usage, particularly due to its economic viability

Two novel coppe(tr) complexes (Fig. 1) with 4-(diethylamino)salicylald.hyd. as ligand (HL) and o-diimine - 2,2'-bipyridine (bipy) or 1,lO-phenanthroline (phen) with potentially antimicrobial activity are described. Complex 1 is a mononuclear copper(Il) complex, [Cu(bipy)(L)]BF+.HzO, whereas complex 2 is a binuclear [Cu(phen)(L)]z(BF+)2. Antimicrobial activities of those complexes, coffesponding Cu(II) salt, o,-diimines (phen and bipy) and ligand HL were studied by examining the minimum inhibitory concentration (MIC) on four Gram-positive and four Gram-negative bacterial species and three fungal strains. Amikacin and fluconazole were used as the standard drugs for the comparison of the MIC values. Cu(II) complexes I and 2 demonstrated significantly stronger antibacterial activities than parent ligands (adiimines and HL) or starting Cu(II) salt. Complex 2 is the most active of all examined compounds. The activity of this complex against E. coli is comparable to the activity of the standard antibiotic amikacin. Unlike increasing antibacterial activity of complexes 1 and2 in regard to all coordinated ligands, antifungal activities showed the opposite trend.

Five Cd(II) complexes, four dinuclear (1-4) and a mononuclear one (5), with the anion of 5-Br-salicylaldehyde (5-Br-salo(-)), were synthesized and characterized as [Cd(5-Br-salo)(2)(CH3OH)](2) (1), [Cd(5-Br-salo)(2) (bipy)](2) (2), [Cd(5-Br-salo)(2)(phen)](2) (3), [Cd(5-Br-salo)(neoc)(NO3)](2) (4) and [Cd(5-Br-salo)(2)(dpamH)] (5). The complexes were characterized by spectroscopy (IR, UV-vis, H-1 NMR), elemental analysis and molar conductivity measurements. The structures for three complexes (2, 3 and 5) were determined by X-ray crystallography providing different coordination modes of the 5-Br-salicylaldehydo ligand. The complexes bind to DNA mainly by intercalation, as concluded by the viscosity measurements and the EB-displacement studies from the EB-DNA complex and present high DNA-binding constants (K-b), as calculated by the Wolfe-Shimer equation and plots. The interaction of the complexes with serum albumins was studied by fluorescence emission spectroscopy and the determined binding constants exhibit relative high values. (C) 2016 Elsevier Ltd. 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] .

The thermal behaviour of a Pt(IV) and a Ru(II) complex coordinated to dibutyl (S,S)-alpha,alpha'-(1,2-ethanediyldiimino)biscyclohexanepropanoate was investigated using thermogravimetry (TG) and differential scanning calorimetry (DSC). The study included an investigation of the thermal decomposition of these complexes in the temperature range of 30 to 590 degrees C and an evaluation of the activation energy for the first decomposition steps. For both metal complexes, broad DSC peaks indicated complex thermal transformation processes. The two-step decomposition of the Pt(IV) complex started at 175 and ended at about 418 degrees C, leaving elemental platinum as the final residue. On the other hand, the Ru(II) analogue decomposed in three stages. Thermal degradation was evident beginning at 144 degrees C and suggested the decomposition of a coordinated ligand as the dominant process. For this complex, the proposed final residue was RuO2. Kinetic parameters for the first decomposition step were obtained by means of the multi-heating rates method, in this case the Kissinger-Akahira-Sunose (KAS) method. The mean activation energy calculated for 0.2 lt alpha lt 0.8 were 122.0 kJ mol(-1) for the Pt(IV) and 118.9 kJ mol(-1) for the Ru(II) complex and decreased constantly, a characteristic of a multi-step process.

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] .

Five dinuclear Cd(II) complexes with the anion of 5-Cl-salicylaldehyde (5-Cl-saloH) were synthesized in the absence or presence of the alpha-diimines: 2,2'-bipyridine (bipy), 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-henanthroline (neoc) or 2,2'-dipyridylamine (dpamH) and characterized as [Cd(5-Cl-salo)(2)(CH3OH)](2) (1), [Cd(5-Cl-salo)(2)(bipy)](2) (2), [Cd(5-Cl-salo)(2)(phen)](2) (3), [Cd(5-Cl-salo)(neoc)(ONO2)](2) (4) and [Cd(5-Cl-salo)(dpamH)(ONO2)](2) (5). The complexes were characterized by spectroscopic techniques (IR, UV-vis, H-1-NMR and C-13-NMR), elemental analysis and molar conductivity measurements. The structures of four complexes (1-3 and 5) were determined by X-ray crystallography, providing all three possible coordination modes of the ligand 5-Cl-salicylaldehyde, i.e. bidentate or tridentate chelating and/or bridging mode. The complexes bind to calf-thymus (Cr) DNA mainly by intercalation, as concluded by the viscosity measurements and present relatively high DNA-binding constants. The complexes exhibit significant ability to displace ethidium bromide (EB) from the EB-DNA complex, thus indirectly proving the intercalation as the most possible binding mode to Cr DNA. (C) 2016 Elsevier B.V. All rights reserved.

Five Cd( II) complexes with the anion of 5- NO2- salicylaldehydeH ( 5- NO2- saloH) in the absence or presence of the alpha-diimine 1,10- phenanthroline ( phen), 2,2'- dipyridylamine ( dpamH), 2,2'- dipyridine ( bipy), or 2,9- dimethyl- 1,10- phenanthroline ( neoc) were synthesized and characterized as [Cd(5- NO2- salo)(2)(CH3OH)(2)] (1), [Cd(5-NO2- salo)(2)( phen)] center dot 2CH3OH center dot H2O (2), [Cd(5- NO2- salo) 2( dpam.)] (3), [Cd-3(5-NO2- salo)(6)(bipy)(2)] (4), and [ Cd(5-NO2-salo)(neoc)(NO3)](2) (5). Based on spectroscopic results ( IR, UV, NMR), elemental analysis and conductivity measurements an octahedral geometry around cadmium metal ion is suggested, with the 5- NO2- salicylaldehyde ligand having different coordination modes. The structures determined by X-ray crystallography verified neutral mononuclear 1-3 and trinuclear 4. Simultaneous TG/DTG-DTA technique was used to analyze the thermal behavior of 1, 2, and 3. The complexes bind tightly to calf-thymus DNA mainly by intercalation, as concluded by DNA viscosity measurements and exhibit significant displacement of EB from the EB- DNA complex.

Thermal decomposition of Co(II) complex with N-benzyloxycarbonylglycinato ligand, [Co(N-Boc-gly)(2)(H2O)(4)]center dot 2H(2)O, in non-isothermal conditions occurs in three complex steps. In order to investigate detail kinetics of first two steps, dehydration and ligand degradation, DTG curves were deconvoluted using product of Gaussian and Lorentzian function. It was shown that process of complex dehydration consists of three, while process of ligand fragmentation consist of five elementary steps. For elementary steps the kinetic triplet (E-a, Z and f(alpha)) was determinated. Kinetic parameters were obtained by application of IKP method. On the basis of Malek's criteria and Sestak-Berggren's method, Sestak-Berggren's model, f(alpha)=alpha(M)(1-alpha)(N) was suggested for all elementary steps, while Master plot method and Perez-Maqueda criteria confirmed suggested reaction models. The thermodynamic activation parameters were calculated for process of complex dehydration, and lifetime for first elementary step of the dehydration and ligand degradation processes was estimated.

Termičko ponašanje kompleksa Co(II), Cd(II) i Zn(II) sa N-benziloksikarbonil--glicinato ligandom: [Co(N-Boc-gly)2(H2O)4]·2H2O, [Cd(N-Boc-gly)2(H2O)2] i[Zn(N-Boc-gly)2] ispitivano je korišćenjem TG, DSC, DTA i DTG krivih dobijenih narazličitim brzinama zagrevanja (od 2,5 do 30 oC min–1), u intervalu temperatura od25 oC do 900 oC. Određeni su mehanizam degradacije kompleksa, entalpije procesadegradacije i termodinamički aktivacioni parametri. Dobijeni rezultati pokazali su da jetermička stabilnost ispitivanih kompleksa u korelaciji sa njihovom strukturom. Prisustvoili odsustvo nekoordinovane i koordinovane vode povezuje strukturu i termičkustabilnost. Razgradnja sva tri kompleksa je stupnjevit proces, a mehanizam je isti za svekomplekse. Razgradnja kompleksa odvija se u tri dobro odvojena i definisana stupnja.Proces razgradnje podrazumeva uklanjanje molekula vode u prvom stupnju (u slučajukompleksa koji sadrže vodu). Posle dehidratacije dolazi do postepene razgradnjedehidratisanog kompleksa. Kinetika složenih stupnjeva termičke razgradnje kompleksaCo(II), Cd(II) i Zn(II) sa N-benziloksikarbonilglicinato ligandom, ispitivana je uneizotermskim uslovima korišćenjem izokonverzionih i neizokonverzionih metoda.Zavisnost Areniusovih parametara od stepena konverzije pokazala je da su svi stupnjevirazgradnje, osim dehidratacije kompleksa Cd(II), složeni procesi koji uključuju više odjednog elementarnog stupnja. Rezultati dobijeni za složene procese analizirani suVjazovkinovim algoritmom i određeni su invarijantni kinetički parametri. Određen jekinetički triplet (energija aktivacije, predeksponencijalni factor i kinetički model) zaelementarni proces dehidratacije kompleksa Cd(II): Einv = 170,4±6,4 kJ mol–1 iZinv = 2,6∙1023. Ustanovljeni kinetički model, „D3”, potvrđen je kriterijumimadefinisanim Malekovom, Perez-Makeda i Master-plot metodom.Složeni procesi: dehidratacija Co(II)-kompleksa, prvi stupanj razlaganjadehidratisanog Co(II)- i Cd(II)-kompleksa i prvi stupanj razgradnje, Thermal behavior of Co(II), Cd(II) and Zn(II) complexes withN-benzyloxycarbonylglycinato ligand: [Co(N-Boc-gly)2(H2O)4]·2H2O,[Cd(N-Boc-gly)2(H2O)2] and [Zn(N-Boc-gly)2] was investigated using the results of TG,DSC, DTA and DTG analysis obtained at different heating rates (2.5 to 30 oC min–1), inthe temperature range from 25 oC to 900 oC. Mechanisms of complex degradation, aswell as degradation enthalpies and thermodynamic activation parameters weredetermined. It is shown that thermal stability of investigated complexes correlates withtheir structures. The presence or absence of uncoordinated and coordinated water affectsthe structure and thermal stability. Degradation of all three complexes is a multi-stepprocess and degradation mechanism is the same for all complexes. The degradation ofcomplexes occurs in three well separated and well defined steps. Degradation processinvolves the loss of water molecules in first step (in the case of complexes containingwater molecules). Dehydration is followed by degradation of dehydrated complex. Thekinetics of multi-step thermal degradation of Co(II), Cd(II) and Zn(II) complexes withN-benzyloxycarbonylglycinato ligand in non-isothermal conditions was studied usingisoconversional and non-isoconversional methods. The dependence of Arrheniusparameters on conversion degree showed that all observed steps of thermal degradation,except dehydration of Cd(II) complex, are complex, involving more than oneelementary step. Results for complex degradation processes were further analyzed byVyazovkin’s algorithm and artificial compensation effect. The kinetic triplet (activationenergy, preexponential factor and kinetic model) for the single-step reaction of Cd(II)complex dehydration was established as Einv = 170.4±6.4 kJ mol–1 and Zinv = 2.6∙1023.The established kinetic model, known as “D3 model”, was confirmed by applicationcriteria defined by Màlek, Perez-Maqueda et. al. as well as Master-plot method.

Termičko ponašanje kompleksa Co(II), Cd(II) i Zn(II) sa N-benziloksikarbonil- -glicinato ligandom: [Co(N-Boc-gly)2(H2O)4]·2H2O, [Cd(N-Boc-gly)2(H2O)2] i [Zn(N-Boc-gly)2] ispitivano je korišćenjem TG, DSC, DTA i DTG krivih dobijenih na različitim brzinama zagrevanja (od 2,5 do 30 oC min–1), u intervalu temperatura od 25 oC do 900 oC. Određeni su mehanizam degradacije kompleksa, entalpije procesa degradacije i termodinamički aktivacioni parametri. Dobijeni rezultati pokazali su da je termička stabilnost ispitivanih kompleksa u korelaciji sa njihovom strukturom. Prisustvo ili odsustvo nekoordinovane i koordinovane vode povezuje strukturu i termičku stabilnost. Razgradnja sva tri kompleksa je stupnjevit proces, a mehanizam je isti za sve komplekse. Razgradnja kompleksa odvija se u tri dobro odvojena i definisana stupnja. Proces razgradnje podrazumeva uklanjanje molekula vode u prvom stupnju (u slučaju kompleksa koji sadrže vodu). Posle dehidratacije dolazi do postepene razgradnje dehidratisanog kompleksa. Kinetika složenih stupnjeva termičke razgradnje kompleksa Co(II), Cd(II) i Zn(II) sa N-benziloksikarbonilglicinato ligandom, ispitivana je u neizotermskim uslovima korišćenjem izokonverzionih i neizokonverzionih metoda. Zavisnost Areniusovih parametara od stepena konverzije pokazala je da su svi stupnjevi razgradnje, osim dehidratacije kompleksa Cd(II), složeni procesi koji uključuju više od jednog elementarnog stupnja. Rezultati dobijeni za složene procese analizirani su Vjazovkinovim algoritmom i određeni su invarijantni kinetički parametri. Određen je kinetički triplet (energija aktivacije, predeksponencijalni factor i kinetički model) za elementarni proces dehidratacije kompleksa Cd(II): Einv = 170,4±6,4 kJ mol–1 i Zinv = 2,6∙1023. Ustanovljeni kinetički model, „D3”, potvrđen je kriterijumima definisanim Malekovom, Perez-Makeda i Master-plot metodom. Složeni procesi: dehidratacija Co(II)-kompleksa, prvi stupanj razlaganja dehidratisanog Co(II)- i Cd(II)-kompleksa i, Thermal behavior of Co(II), Cd(II) and Zn(II) complexes with N-benzyloxycarbonylglycinato ligand: [Co(N-Boc-gly)2(H2O)4]·2H2O, [Cd(N-Boc-gly)2(H2O)2] and [Zn(N-Boc-gly)2] was investigated using the results of TG, DSC, DTA and DTG analysis obtained at different heating rates (2.5 to 30 oC min–1), in the temperature range from 25 oC to 900 oC. Mechanisms of complex degradation, as well as degradation enthalpies and thermodynamic activation parameters were determined. It is shown that thermal stability of investigated complexes correlates with their structures. The presence or absence of uncoordinated and coordinated water affects the structure and thermal stability. Degradation of all three complexes is a multi-step process and degradation mechanism is the same for all complexes. The degradation of complexes occurs in three well separated and well defined steps. Degradation process involves the loss of water molecules in first step (in the case of complexes containing water molecules). Dehydration is followed by degradation of dehydrated complex. The kinetics of multi-step thermal degradation of Co(II), Cd(II) and Zn(II) complexes with N-benzyloxycarbonylglycinato ligand in non-isothermal conditions was studied using isoconversional and non-isoconversional methods. The dependence of Arrhenius parameters on conversion degree showed that all observed steps of thermal degradation, except dehydration of Cd(II) complex, are complex, involving more than one elementary step. Results for complex degradation processes were further analyzed by Vyazovkin’s algorithm and artificial compensation effect. The kinetic triplet (activation energy, preexponential factor and kinetic model) for the single-step reaction of Cd(II) complex dehydration was established as Einv = 170.4±6.4 kJ mol–1 and Zinv = 2.6∙1023. The established kinetic model, known as “D3 model”, was confirmed by application criteria defined by Màlek, Perez-Maqueda et. al. as well as Master-plot method.

In this work, the syntheses and characterization of two novel compounds of adamantane-1-sulfonic acid (1-AdSO(3)H) with cobalt(II) and cadmium(II) are reported. The results of single crystal X-ray analysis of the compounds revealed that adamantane-1-sulfonate (1-AdSO(3)(-)) in the monoanionic form plays different roles in the investigated compounds. Namely, while in compound [Co(H2O)(6)](1-AdSO(3))(2), six water molecules are coordinated to the cobalt(II) ion and 1-AdSO(3)(-) serves as a counter ion, in compound [Cd(H2O)(4)(1-AdSO(3))(2)], two molecules of 1-AdSO(3)(-) are trans-coordinated to the cadmium(II) ion as a monodentate (O)-ligand and the other coordination sites are occupied by water molecules. The obtained compounds showed moderate activity against Artemia salina., U ovom radu prikazana je sinteza i karakterizacija dva nova jedinjenja adamantan-1-sulfonske kiseline (1-AdSO3H) sa kobaltom(II) i kadmijumom(II). Rezultati rend- genske strukturne analize datih jedinjenja ukazuju da monoanjon adamantan-1-sulfonata (1-AdSO3 pokazuje različit afinitet prema Co(II) i Cd(II) jonima). U kompleksu [Co(H2O)6](1-AdSO3)2, šest molekula vode se koordinuje za Co(II) jon, dok 1-AdSO3 ima ulogu kontrajona. U kompleksu [Cd(H2O)4(1-AdSO3)2] dva jona 1-AdSO3 su koordinovana za Cd(II) jon kao monodentati u trans položaju preko kiseonikovih atoma, dok su ostala koordinaciona mesta zauzeta molekulima vode. Dobijena jedinjenja su pokazala umerenu aktivnost na Artemia salina.

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.

The kinetics and mechanism of the structural transformation of 2-(5-ethoxycarbonylmethyl-4-oxothiazolidin-2-ylidene)-N-(2-phenylethyl)-ethanamide in non-isothermal conditions were studied by using isoconversion as well as non-isoconversion techniques. It was shown that the crystal, Z-form of compound, was stable in the temperature range from room temperature to melting point, when E-form of compound was formed. This process involves the breaking of crystal structure and the forming of glass material as a new phase, which by cooling forms crystal of the E-form of compound very slowly. The dependences of kinetic parameters on fractional extent conversion were determined indicating a very complex process which involves more than one elementary step, as can be expected for most solid state reactions. The possible mechanism of the process was discussed according to the algorithm concerning the form of these dependences. The evaluation of kinetics parameters and isokinetic relationships were done by combination of model fitting and model-free approach.

Multi-step thermal degradation of coordination polymer [Cd(N-Boc-gly)(2)(H2O)(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(alpha) = 3/2(1 - alpha)(2/3)[1 - (1 - alpha)(1/3)](-1). E-inv = 170.4 +/- 6.4 kJ mol(-1) and Z(inv) =2.6 x 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 (alpha), 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 C6H5CH2O- fragments in two parallel steps. The third step of degradation, ascribed to the loss of two -C(=O)NHCH2- fragments, is complicated by changing kinetically to diffusion control. (C) 2011 Elsevier B.V. All rights reserved.

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 A degrees C min(-1)), from room temperature to about 900 A degrees 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.

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) Å, b = 24.1516(5) Å, c = 15.4471(3) Å, β = 99.930(2)°, V = 5284.74(19) Å3 and Z = 12, i.e. three molecules per asymmetric unit.