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EN
N-(3-Bromo-4-hydroxy-5-methoxybenzylidene)-4-Bromobenzenamine was synthesized. This was further used to synthesize Co(II), Ni(II) and Co(II) based metal complexes and characterized by FT-IR, Elemental analysis, ESI Mass and UV spectroscopy.
EN
A novel series of complexes with the formula [MLCl] [M = Co(II) (1), Ni(II) (2), Cu(II) (3), Zn(II) (4)] arising from Pyridyl ligand, N,N’-bis(1-(2-pyridyl)ethylidene)-2,2-dimethylpropane-1,3-diamine), ligand, L, was synthesized and investigated by elemental analyses, FT-IR, 1H and 13C NMR, Powder XRD, and thermal analyses. TGA analysis indicated that all complexes degraded in three different steps, while the PXRD examination showed well-defined sharp crystalline peaks for the complexes, indicating significant crystallinity. The antiproliferative activity of the ligand and its complexes were also evaluated in vitro against the HeLa (Human Cervical Cancer Cells) and HCT116 (Colon Cancer Cells) cell lines. The findings suggested complex 4 to be potential anticancer agent against these cell lines. In addition, ligand and its complexes also exhibited considerable emission properties.
3
Content available remote Metal complexes of xanthan gum
80%
EN
lnteractions of selected paramagnetic transition metal salts [NI (II) Co (II) Cu (II) Fe(III), Mn(II)] with, xanthan gum are described. The conductivity, DSC/TG/DTG measurements, and EPR measurements produced evidence for the formation of the Werner-type complexes of metal central atoms with polysaccharide ligand. The polysaccharide hydroxyl groups and the carboxylic groups of xanthan gum were involved in ligation of the central atom.
EN
A new hydrazone ligand (HL), [2-(4-methoxyphenylamino)-N'-(thio phen-2-yl-methy - lene)acetohydrazide], was prepared and characterized. The ligand reacted with Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Hf(IV), Ru(III) and ZrO(II) ions to yield mononuclear complexes. The obtained metal complexes have been characterized using elemental and thermal analyses (TG and DTA), IR, UV-Vis and ESR as well as magnetic moment and molar conductance measurements. The results showed that the hydrazone behaves as a neutral bidentate ligand which coordinates with the metal ions via the thiophene sulphur atom and imido N-H as in case of complexes of the general formula: [M(HL)2X2]×nH2O, where M = Cu(II), X = OAc, n = 2; M = Co(II), X = Cl and Br, n = 0, 1, re spec tively; M = Ni(II), X = OAc, n = 1; M = Mn(II), X = OAc, n = 1; M = Zn(II), X = OAc, n = 0; M = ZrO(II), X = Cl, n = 5; [M(HL)2(NO3)]×NO3×nH2O, where M = Co(II), n = 1; M = Zn(II), n = 0; [M(HL)X2]×nH2O, where M = Cu(II), X = Cl, n = 1; M = Co(II), X = OAc, n = 1 and [Ru(HL)2Cl2]Cl. The ligand also coordinates via the carbonyl oxygen atom and azomethine ni tro gen atom as in case of [Cu(HL)(NO3)]NO3×1.5H2O complex and via the carbonyl oxygen atom and the aniline N-H as in case of complexes [Ni(HL)Cl2]×H2O and [Ni(HL)2(NO3)]×NO3×4H2O. As a tridentate monobasic ligand HL co or di nates through the thiophene sul phur atom, azomethine ni tro gen atom and the enolic ox y gen atom as in case of complex [Hf(L)Cl3]×3H2O. The geometrical shapes of complexes also have been elucidated. The thermal behavior of some metal complexes has also been studied using TG and DTA.
EN
A new series of tricarbonyl compounds, in which the keto groups are at tached to olefinic linkages, have been synthesized by the reaction between acetoacetanilide and aromatic aldehydes (2-chlorobenzaldehyde, 4-chlorobenzaldehyde, 4-hydroxybenzaldehyde and vanillin) under specified conditions. Their IR, 1H NMR and mass spectral data revaealed that only one of the carbonyl groups is enolised and engaged in intramolecular hydrogen bonding. Neutral bidentate coordination of these compounds with Ni(II), Cu(II) and Zn(II) has been established on the basis of analytical and spectral data.
6
Content available remote Chelating ability of proctolin tetrazole analogue
80%
EN
The aim of the investigation was to establish the chelating ability of a new proctolin analogue of the sequence Arg-Tyr-LeuΨ[CN4]Ala-Thr towards copper(II) ions. The insertion of the tetrazole moiety into the peptide sequence has considerably changed the coordination ability of the ligand. Potentiometric and spectroscopic (UV-Vis, CD, EPR) results indicate that the incorporation of 1,5-disubstituted tetrazole ring favours the formation of a stable complex form of CuH-1L. This 4N coordination type complex is the dominant species in the physiological pH range. The tetrazole moiety provides one of these nitrogens. The data indicate that Cu(II) ions are strongly trapped inside the peptide backbone. These findings suggest that Cu(II) can hold peptide chains in a bent conformation. This bent conformation may be essential for bioactivity of the tetrazole peptides.
EN
A novel macrocyclic Knoevenagel Schiff base ligand has been designed and synthesized using 3-cinnamalideneacetoacetanilide and 4,4'-diaminodiphenylmethane. It acts as a tetradentate and strongly conjugated to form acationic solid complex with CuCl2/NiCl2/CoCl2/ZnCl2/MnCl2/CdCl2/HgCl2/VOSO4. The formed ligand and the complexes were characterized by usual spectral and analytical techniques. All the synthesized complexes were characterized by microanalytical data, magnetic susceptibility measurements, IR, UV-Vis, 1H-NMR, ESR and mass spectral techniques. They exhibit square-planar geometry except oxovanadium complex, which has square-pyramidal geometry. The electrolytic behaviour and monomeric nature of the com plexes were confirmed from their conductance data and magnetic susceptibility values. The X-band ESR spectra of Cu(II) and VO(IV) complexes in DMSO at 300 and 77 K were recorded and their salient features are reported. The in vitro antimicrobial activi ies of the investigated compounds were tested against few microorganisms by well-diffusion technique. It was found that the metal complexes have higher activity than the ligand. The cleavage activity of all the complexes was examined on CT-DNA using gel electro phoresis experiment in the presence of H2O2. From the data, it was found that oxovanadium, zinc and manganese complexes cleave DNA through redox chemistry.
EN
This article discusses coordination preferences of N-substituted iminodi(methylenephosphonic) acids to the different metal ions in an aqueous solution. These ligands exhibit high complexation efficiency towards divalent metal ions. This results from both dinegatively charged phosphonate groups as well as the imino nitrogen present in their structure. A significant preference for an equimolar stoichiometry has been demonstrated in these systems. The only exception is the N-2-methyltetrahydrofuryliminodi( methylenephosphonic) acid with a tetrahydrofuryl moiety, placed in the sterically favoured position that allows its oxygen atom to be an effective metal binding site. Specific interactions between metal ions and furyl oxygen results in higher binding ability of this ligand and a formation of 1:2 species. Coordination properties of iminodi- (methylenephosphonic) acids are important factors to understand the role of the ligands and metal ions in biological systems. A summary presented in this review points on the direction of the research for future work in this area, which should be developed.
EN
Abstract: The main problem of modern cancer therapy is their resistance to the drugs used and the toxicity of drugs to healthy cells of the human body. Hope is natural substances that are protective of cells and often support the action of standard anticancer chemotherapy. Among them are selenium compounds. In the present study, we examined the cytotoxic and genotoxic potency of doxorubicin (DOX) metal complexes as new anticancer drug candidates. We also measured the effect of simultaneous administration of seleno –L-methionine as biologically active agent with DOX and its complexes with Mn, Mg, Fe, Co and Ni in prokaryotic model - Escherichia coli RFM443 with plasmid transcriptional fusion of recA promoter and luxCDABE as a reporter gene. The results obtained by us, indicate high biological activity of metal complexes with doxorubicin. The strongest modulatory effect was observed using the DOX complexes with Co and Ni compared to the DOX. The DOX complexes with Mg, Mn and Fe also showed relatively high biological activity. Simultaneous bacteria culture treatment with SeMet decreased the values of the DOX and its metal complexes cyto- and genotoxic parameters. These results encourage further research to assess the value of the doxorubicin metal complexes as new cytostatic drug candidates. While SeMet may be considered as therapeutic option in cancer treatment as modulation agent in anti-cancer therapy.
EN
Naphthylazo and benzothiazolylazo derivatives of three beta-diketones in which the diketo function is attached directly to olefinic link ages (dicinnamoyl methane, acetyl cinnamoyl methane and benzoyl cinnamoyl methane) have been synthesized and characterized. Analytical, IR, 1H NMR and mass spectral data indicate that the naphthylazo derivatives exist in the intramolecularly hydrogen bonded keto-hydrazone form and benzothiazolylazo derivatives in the intramolecularly hydrogen bonded azo-enol tautomeric form. In the [ML2] complexes [M = Ni(II), Cu(II), Zn(II)] the naphthylazo derivatives function as monobasic bidentate in which one of the hydrazone nitrogen and keto oxygen are involved in bonding with the metal ion. Monobasic tridentate coordination of the benzo -thiazolylazo derivatives in their [ML2] complexes has been established on the basis of analytical and spectral data.
EN
A novel tetradentate N2O2 type Schiff base, synthesized from 1-phenyl-2,3-dimethyl-4-aminopyrazol-5-one(4-aminoantipyrine) and 3-salicylidene-acetylacetone, forms stable complexes with transition metal ions such as CuII, NiII, CoII and ZnII in ethanol. Microanalytical data, magnetic susceptibility, IR, UV-Vis.,1H-NMR, ESR and Mass spectral techniques were used to confirm the structures. Electronic absorption spectra of the complexes suggest a square-planar geometry around the central metal ion. These complexes show higher conductance values, supporting their electrolytic nature. The monomeric nature of the complexes was confirmed from their magnetic susceptibility values. Cyclic voltammogram of the copper(II) and nickel(II) complexes in DMSO solution at 300 K were recorded and the results are discussed. The X-band ESR spectra of the copper complex were recorded and the molecular orbital coefficient values were calculated from the spectra. The in vitro antimicrobial activities of the investigated compounds were tested against bacteria such as Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis and Escherichia coli and fungi like Aspergillus niger and Rhizoctonia bataicola. Most of the metal chelates show higher antimicrobial activity for the above microorganisms than that of the free ligand.
EN
Two new vic-dioxime, N-(4-amino-1-benzyl piperidine)-anti-phenylglyoxime (L1H2) and N-(4-amino-1-benzyl piperidine)-anti-glyoxime (L2H2) were prepared by the reaction of anti-phenylchloroglyoxime and anti-monochloroglyoxime with 4-amino- 1-benzyl piperidine in absolute THF at –15°C. Mononuclear nickel(II), copper(II), and cobalt(II) complexes have a metal-ligand ratio of 1:2 in which the ligands coordinate through the two nitrogen atoms as do most vic-dioximes. The ligands and their Co(II), Cu(II), and Ni(II) complexes were characterized by elemental analyses, FT-IR, UV-vis, 1H-NMR and 13C-NMR, magnetic susceptibility measurements, electrical conductivity measurements and cyclic voltammetry. The electrical conductivity of Ni(II), Co(II), and Cu(II) metal complexes were measured using Four-Point Probe analysis. The electrochemical behavior of theNi(II), Co(II), andCu(II) complexeswere investigated by cyclic voltammetry in DMSO.
EN
Thiosemicarbazones ligands, isatin-3-thiosemicarbazone (HIT) and N-acetylisatin-3- thiosemicarbazone (HAIT), which have tridentate ONN coordinating sites were prepared. The complexes of both ligands with Cu(II), Co(II), Ni(II), Fe(III), Cd(II), Zn(II), Mn(II) and UO2(VI) ions were isolated. The ligands and their metal complexes were characterized by elemental analyses, IR, UV-Vis and mass spectra, also by conductance, magnetic moment and TG-DSC measurements. All the transition metal complexes have octahedral configurations, except Cu-complexes, which were found to have the squareplanar geometry and theUO2(VI) complexes which have coordination number 8 and may acquire the distorted dodecahedral geometry. Thermal studies explored the possibility of obtaining new complexes. Inversion from octahedral to square-planar configuration occurred upon heating the parent Ni-HAIT complex to form the corresponding pyrolytic product. The antifungal activity against the tested organisms showed that some metal complexes enhanced the activity with respect to the parent ligands.
EN
Two new vic-dioxime, N-(4-amino-1-benzyl piperidine)-anti-phenylglyoxime (L1H2) and N-(4-amino-1-benzyl piperidine)-anti-glyoxime (L2H2) were prepared by the reaction of anti-phenylchloroglyoxime and anti-monochloroglyoxime with 4-amino- 1-benzyl piperidine in absolute THF at -15°C. Mononuclear nickel(II), copper(II), and cobalt(II) complexes have a metal-ligand ratio of 1:2 in which the ligands coordinate through the two nitrogen atoms as do most vic-dioximes. The ligands and their Co(II), Cu(II), and Ni(II) complexes were characterized by elemental analyses, FT-IR, UV-vis, 1H-NMR and 13C-NMR, magnetic susceptibility measurements, electrical conductivity measurements and cyclic voltammetry. The electrical conductivity of Ni(II), Co(II), and Cu(II) metal complexes were measured using Four-Point Probe analysis. The electrochemical behavior of theNi(II), Co(II), andCu(II) complexeswere investigated by cyclic
EN
The structure and fragmentation mechanism of metal (Mn(II), Al(III) and Cu(II)) complexes of xanthone glycosides as well as metal coordination sites were investigated by electrospray ionization tandem mass spectrometry. Four Mn(II) complexes of xanthone glycoside with different stoichiometric ratios were observed from swertianin 7-Orhamnosyl( 1 rarr 2)xyloside, swertianin 7-O-xylosyl(1 rarr 2)xyloside and swertianolin, while only two complexes were formed for 3,7,8-trimethoxy-1-O-primeverosyloxanthone, 2,3,5-trimethoxy-1-O-primeverosyloxanthone and 2,3,4,5-tetramethoxy-1-Oprimeverosyloxanthone, respectively. For xanthone glycoside-Cu(II) complexes, three complexes with different stoichiometric ratios were observed from swertianin 7-Orhamnosyl( 1 rarr 2)xyloside, swertianin 7-O-xylosyl(1 rarr 2) xyloside and swertianolin, but only one Al(III) complexes were formed for above three xanthone glycosides. Based on the analysis of metal complexes by tandem mass spectrometry, a fragmentation mechanism for 1:1 swertianin 7-O-rhamnosyl(1rarr 2)xyloside-Mn(II) complex was proposed and the structures of four swertianin 7-O-rhamnosyl(1 rarr 2)xyloside-Mn(II) complexes were interpreted. In addition, the hydroxyl groups in the oligosaccharide chains, the hydroxyl groups substituted at C-1 and C-8, and the carbonyl group in the C-ring of the aglycone, were proved to be the dominant coordination sites in the xanthone glycosidemetal complexes.
EN
The electrochemical behavior of some sulpha drug-Schiff bases at a mercury electrode was examined in the Britton-Robinson universal buffer of various pH values (2.5–11.7) containing 20% v/v) of ethanol using DC-polarography, cyclic voltammetry and controlled-potential electrolysis. The DC-polarograms and cyclic voltammograms of the examined compounds exhibited a single, 2-electron, irreversible, diffusion-controlled cathodic step within the entire pH range which is attributed to the reduction of the azomethine group-CH=N- to -CH2-NH-. The symmetry transfer coefficient (α) of the electrode reaction and the diffusion coefficient (D 0) of the reactant species were determined. The electrode reaction pathway of the compounds at the mercury electrode was suggested to follow the sequence: H+, e−, e−, H+. The dissociation constant of the sulpha drug-Schiff bases, the stability constant and stoichiometry of their complexes with various divalent transition metal ions (Mn2+, Co2+, Ni2+, Cu2+ and Zn2+) were determined potentiometrically at room temperature. [...]
EN
The binary and ternary complex formations of poly(methyl vinyl ether-co-maleic anhydride) (PMVEMA) with copper ions and with bovine serum albumin (BSA) in the presence of copper ions in phosphate buffer solution at pH = 7 were examined by the techniques of UV-visible, fluorescence, dynamic light scattering, atomic force microscopy measurements. In the formation of binary complexes of PMVEMA-Cu(II), the addition of copper ions to the solution of PMVEMA in phosphate buffer solution at pH = 7 forms homogeneous solutions when the molar ratio of Cu(II)/MVEMA is 0.5. Then the formations of ternary complexes of PMVEMA-Cu(II)-BSA were examined. Study analysis revealed that the toxicities of polymer-metal and polymer-metal-protein mixture solutions depend on the nature and ratio of components in mixtures.
18
Content available remote Karborany i metalokarborany. Część 2. Metalokarborany
60%
EN
Metallacarboranes are cluster compounds that incorporate metal atoms and hydrides of carbon and boron in their polyhedral skeleton. A large number of metals such as Sc, Cr, Mg, Fe, Co, Ni, Cu, Zr, Mn, Ru, Pd, Yb, Ta, Pt, Au have been incorporated as cluster vertices. The chemistry of metallacarboranes originated with observation that the open face of dicarbollide ion (C2B9HII2-) is very similar to the cyclopentadienyl ligand (Cp-) and can form metallacarboranes in the same way as Cp- forms sandwich type complexes. Metallacarboranes are stable, colored crystalline solids that are soluble in organic solvents and well survive exposure to air. Many of them undergo reversible chemical or electrochemical oxidation and reduction. Metal-carborane complexes find an increasing number of applications in catalysis, siloxane-linked polymers, solvent extraction of radionuclides from nuclear waste, materials for nonlinear optics, medicinal diagnosis and treatment, and others.
EN
The binary and ternary complex formations of poly(methyl vinyl ether-co-maleic anhydride) (PMVEMA) with copper ions and with bovine serum albumin (BSA) in the presence of copper ions in phosphate buffer solution at pH = 7 were examined by the techniques of UV-visible, fluorescence, dynamic light scattering, atomic force microscopy measurements. In the formation of binary complexes of PMVEMA-Cu(II), the addition of copper ions to the solution of PMVEMA in phosphate buffer solution at pH = 7 forms homogeneous solutions when the molar ratio of Cu(II)/MVEMA is 0.5. Then the formations of ternary complexes of PMVEMA-Cu(II)-BSA were examined. Study analysis revealed that the toxicities of polymer-metal and polymer-metal-protein mixture solutions depend on the nature and ratio of components in mixtures.
PL
Kompleksy metali odgrywają istotną rolę zarówno w rolnictwie, jak również chemii farmaceutycznej i przemysłowej. Zasady Schiffa są produktami kondensacji pierwszorzędowych amin i związków karbonylowych. Związki te oraz ich kompleksy z metalami są coraz częściej stosowane jako katalizatory, polimery i barwniki. W artykule przedstawiono właściwości zasad Schiffa oraz korzyści wynikające z ich stosowania w różnych gałęziach przemysłu.
EN
Metal complexes play an important role in agriculture as well as industrial and pharmaceutical chemistry. Schiff bases are the condensation products of primary amines and carbonyl compounds. Schiff bases and their metal complexes are increasingly being used as catalysts, polymers and dyes. This paper reviews the properties of Schiff bases and benefits of their use in various branches of industry.
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