Synthesis,physico-chemical investigations and biological studies on Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes with p -amino acetophenone isonicotinoyl hydrazone

Complexes of the type [M(painh)(H₂O)₂X], where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); X = Cl₂ or SO₄; painh = p-amino acetophenone isonicotinoyl hydrazone, have been synthesized and characterized by spectral and other physico-chemical techniques. The synthesized complexes are stable powders, insoluble in common organic solvents such as ethanol, benzene, carbon tetrachloride, chloroform and diethyl ether, and are non-electrolytes. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) studies show that the organic ligand decomposes exothermically through various steps. TGA and Infrared (IR) spectral studies indicate the presence of coordinated water in the metal complexes. Magnetic susceptibility measurements and electronic spectra suggest that Mn(II), Co(II), and Ni(II) complexes are paramagnetic with octahedral geometry, whereas Cu(II) complexes have distorted octahedral geometry. The neutral bidentate ligand bonds through >C=O and >C=N–groups in all the complexes. Electron Spin Resonance (ESR) spectra in the solid state show axial symmetry for [Cu(painh)(H₂O)₂(SO₄)] and elongated rhombic symmetry for [Cu(painh)(H₂O)₂Cl₂], suggesting an elongated tetragonally-distorted octahedral structure for both complexes. X-ray powder diffraction parameters for two complexes correspond to tetragonal and orthorhombic crystal lattices. The metal complexes show fair antifungal activity against Rizoctonia sp., Aspergillus sp., Stemphylium sp., and Penicillium sp. and appreciable antibacterial activity against Pseudomonas sp. and Escherichia coli.     

Spectral,thermal and magnetic investigations of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) 4-methylphthalates

Conditions for the preparation of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) 4-methylphthalates were investigated and their composition, solubility in water at 295 K and magnetic moments were determined. IR spectra and powder diffraction patterns of the complexes prepared with molar ratio of metal to organic ligand of 1.0:1.0 and general formula: M [ CH₃C₆H₃(CO₂)₂]·nH₂o (n=1-3) were recorded and their decomposition in air were studied. During heating the hydrated complexes are dehydrated in one (Mn, Co, Ni, Zn, Cd) or two steps (Cu) and next the anhydrous complexes decompose to oxides directly (Cu, Zn), with intermediate formation of carbonates (Mn, Cd), oxocarbonates (Ni) or carbonate and free metal (Co). The carboxylate groups in the complexes studied are mono- and bidentate (Co, Ni), bidentate chelating and bridging (Zn) or bidentate chelating (Mn, Cu, Cd). The magnetic moments for paramagnetic complexes of Mn(II), Co(II), Ni(II) and Cu(II) attain values 5.92, 5.05, 3.36 and 1.96 M.B., respectively. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis,structural studies and bio-activity of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes with p -amino acetophenone salicyloyl hydrazone

Complexes of the type [M(pash)Cl] and [M(Hpash)(H₂O)SO₄] (M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); Hpash = p-amino acetophenone salicyloyl hydrazone) have been synthesized and characterized by elemental analyses, molar electrical conductance, magnetic moments, electronic, ESR and IR spectra, thermal studies and X-ray powder diffraction. All the complexes are insoluble in common organic solvents and are non-electrolytes. The magnetic moment values and electronic spectra indicate a square-planar geometry for Co(II), Ni(II) and Cu(II) chloride complexes and spin-free octahedral geometry for the sulfato complexes. The ligand coordinates through >C=N–,–NH₂ and a deprotonated enolate group in all the chloro complexes, and through >C=N–, >C=O and–NH₂ in the sulfato complexes. Thermal analyses (TGA and DTA) of [Cu(pash)Cl] show a multi-step exothermic decomposition pattern. ESR spectral parameters of Cu(II) complexes in solid state at room temperature suggest the presence of the unpaired electron in d _{x ² ? y ²} . X-ray powder diffraction parameters for [Cu(pash)Cl] and [Ni(Hpash)(H₂O)SO₄] correspond to tetragonal and orthorhombic crystal lattices, respectively. The complexes show a fair degree of antifungal activity against Aspergillus sp., Stemphylium sp. and Trichoderma sp. and moderate antibacterial activity against E. coli and Clostridium sp.     

Synthesis,characterization, equilibrium studies,and biological activity of complexes involving copper(II), 2-aminomethylthiophenyl-4-bromosalicylaldehyde Schiff base,and selected amino acids

Ternary complexes of copper(II) with 2-aminomethylthiophenyl-4-bromosalicylaldehyde (ATS) and some amino acids have been isolated and characterized by elemental analyses, IR, magnetic moment, molar conductance, UV–vis, mass spectra, and ESR. The proposed general formulas of the prepared complexes are [Cu(ATS)(AA)]·nH₂O (where AA?=?glycine, alanine, and valine). The low molar conductance values suggest the non-electrolytic nature of the complexes. IR spectra show that ATS is coordinated to copper in a bidentate manner through azomethine-N and phenolic-OH. The amino acids also are monobasic bidentate ligands via amino and ionized carboxylate groups. The magnetic and spectral data indicate the square-planar geometry of Cu(II) complexes. The geometry of the Cu(II) complexes has been fully optimized using parameterized PM3 semiempirical method. The Cu–N bond length is longer than that of Cu–O in the isolated complexes. Also, information is obtained from calculations of molecular parameters for all complexes including net dipole moment of the metal complexes, values of binding energy, and lipophilicity value (log P). The antimicrobial activity studies indicate significant inhibitory activity of complex 3 against the selected types of bacteria. The mixed ligand complexes have also been studied in solution state. Protonation constants of ATS and amino acids were determined by potentiometric titration in 50% (v/v) DMSO–water solution at ionic strength of 0.1?M NaCl. ATS has two protonation constants. The binary and ternary complexes of copper(II) involving ATS and some selected amino acids (glycine, alanine, and valine) were examined. Copper(II) forms [Cu(ATS)], [Cu(ATS)₂], [Cu(AA)], [Cu(AA)₂], and [Cu(ATS)(AA)] complexes. The ternary complexes are formed in a simultaneous mechanism.     

Ag(I), Cu(II), and Cd(II) sulfacetamide complexes: Synthesis,spectral, thermal study,and antimicrobial activity assessment

Sulfacetamide complexes of Ag(I), Cu(II), and Cd(II) were synthesized and characterized by the elemental analyses and IR and ¹H NMR spectra. Structural assessment revealed two modes of coordination in the sulfacetamide complexes, showing that sulfacetamide reacts as a bidentate ligand and coordinates to Ag(I) and Cd(II) through the amido and sulfonyl oxygens and to Cu(II) through the NH₂ nitrogen. Molar conductance measurements in DMSO showed that both the complexes are nonelectrolytes in nature, which allowed they to be assigned the formulas [Ag(SAM-Na)(NO₃)H₂O)]·3H₂O, [Cu(SAM-Na)₂(Cl)₂], and [Cd(SAM-Na)(Cl)₂]·10H₂O. The kinetic and thermodynamic parameters of the thermal decomposition reactions of the complexes were estimated from the TG/DTG curves by the Coats–Redfern and Horowitz–Metzeger methods. The surface morphology of sulfacetamide complexes was scanned using X-ray powder diffraction (XRD) and scanning electron microscope (SEM) analyses.     

Synthesis, spectroscopic, thermal Studies, antimicrobial activities and crystal structures of Co(II), Ni(II), Cu(II) and Zn(II)-orotate complexes with 2-methylimidazole

The 2-methylimidazole complexes of Co(II), Ni(II), Cu(II) and Zn(II) orotates, mer-[Co(HOr)(H₂O)₂(2-meim)₂] (1), mer-[Ni(HOr)(H₂O)₂(2-meim)₂] (2), [Cu(HOr)(H₂O)₂(2-meim)] (3) and [Zn(HOr)(H₂O)₂(2-meim)] (4), were synthesized and characterized by elemental analysis, spectral (UV–Vis and FT-IR) methods, thermal analysis (TG, DTG and DTA), magnetic susceptibility, antimicrobial activity studies and single crystal X-ray diffraction technique. The complexes 1 and 2 have distorted octahedral geometries with two monodentate 2-methylimidazole and one bidentate orotate and two aqua ligands. The complexes 3 and 4 have distorted square pyramidal and trigonal bipyramidal geometry, respectively, with one 2-methylimidazole, bidentate orotate and aqua ligands. The orotate coordinated to the metal(II) ions through deprotonated nitrogen atom of pyrimidine ring and oxygen atom of carboxylate group as a bidentate ligand. The antimicrobial activities of 1 and 4 were found to be more active gram (+) than gram (−) and 4 could be use for treatment Staphylococcus aureus.     

Vitamin B13 Complexes of Nickel(II) and Copper(II) with Ethanolamine: Syntheses,Crystal Structures,Spectroscopic and Thermal Studies

Fac‐bis(ethanolamine)orotatonickel(II), [Ni(HOr)(ea)₂] and mer‐bis(ethanolamine)orotatocopper(II) dihydrate, [Cu(HOr)(ea)₂]· 2H₂O were synthesized and characterized by elemental analysis, FT‐IR, UV‐Vis Spectroscopy and thermal analysis. In addition, their solid‐state structures were determined by single crystal X‐ray diffraction studies. Both the fac‐[Ni(HOr)(ea)₂] (1) and mer‐[Cu(HOr)(ea)₂]·2H₂O (2) complexes are isomorphous and crystallize in the triclinic space group . The Ni²⁺ and Cu²⁺ ions are coordinated by two neutral ea ligands and one orotate dianion in a distorted octahedral fashion. The ea ligand acts as a bidentate donor through the amine N and hydroxyl O atoms, while orotate dianion is coordinated through deprotonated N3 pyrimidine atom and carboxylate oxygen atom as a bidentate ligand. Thermal decompositions of the complexes are studied in over the range 20–600 °C on heating in a static air atmosphere.     

Potentiometric and spectrometric study: Copper(II), nickel(II) and zinc(II) complexes with potentially tridentate and monodentate ligands

Equilibrium and solution structural study of mixed-metal-mixed-ligand complexes of Cu(II), Ni(II) and Zn(II) with L-cysteine, L-threonine and imidazole are conducted in aqueous solution by potentiometry and spectrophotometry. Stability constants of the binary, ternary and quaternary complexes are determined at 25 ±1°C and in I= 0.1 M NaClO₄. The results of these two methods are made selfconsistent, then rationalized assuming an equilibrium model including the species H₃A, H₂A, A, BH, B, M(OH), M(OH)₂, M(A), MA(OH), M(B), M(A)(B), M₂(A)₂(B), M₂(A)₂(B-H), M¹M²(A)₂(B) and M¹M²(A)₂(B-H) (where the charges of the species have been ignored for the sake of simplicity) (A = L-cysteine, L-threonine, salicylglycine, salicylvaline and BH = imidazole). Evidence of the deprotonation of BH ligand is available at alkalinepH. N₁H deprotonation of the bidentate coordinated imidazole ligand in the binuclear species atpH > 70 is evident from spectral measurements. Stability constants of binary M(A), M(B) and ternary M(A)(B) complexes follow the Irving-Williams order.     

Ligational behaviour of lomefloxacin drug towards Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Th(IV) and UO(2)(VI) ions: synthesis, structural characterization and biological activity studies

Nine new mononuclear Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Th(IV) and UO₂(VI) complexes of lomefloxacin drug were synthesized. The structures of these complexes were elucidated by elemental analyses, IR, XRD, UV–vis, ¹H NMR as well as conductivity and magnetic susceptibility measurements and thermal analyses. The dissociation constants of lomefloxacin and stability constants of its binary complexes have been determined spectrophotometrically in aqueous solution at 25 ± 1 °C and at 0.1 M KNO₃ ionic strength. The discussion of the outcome data of the prepared complexes indicate that the lomefloxacin ligand behaves as a neutral bidentate ligand through OO coordination sites and coordinated to the metal ions via the carbonyl oxygen and protonated carboxylic oxygen with 1:1 (metal:ligand) stoichiometry for all complexes. The molar conductance measurements proved that the complexes are electrolytes. The powder XRD study reflects the crystalline nature for the investigated ligand and its complexes except Mn(II), Zn(II) and UO₂(II). The geometrical structures of these complexes are found to be octahedral. The thermal behaviour of these chelates is studied where the hydrated complexes lose water molecules of hydration in the first steps followed by decomposition of the anions, coordinated water and ligand molecules in the subsequent steps. The activation thermodynamic parameters are calculated using Coats–Redfern and Horowitz–Metzger methods. A comparative study of the inhibition zones of the ligand and its metal complexes indicates that metal complexes exhibit higher antibacterial effect against one or more bacterial species than the free LFX ligand. The antifungal and anticancer activities were also tested. The antifungal effect of almost metal complexes is higher than the free ligand. LFX, [Co(LFX)(H₂O)₄]·Cl₂ and [Zn(LFX)(H₂O)₄]·Cl₂ were found to be very active with IC50 values 14, 11.2 and 43.1, respectively. While, other complexes had been found to be inactive at lower concentration than 100 μg/ml.     

New Complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) with 3,3-dimethylglutaric Acid

Conditions for the preparation of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II)3,3-dimethylglutarates were investigated and their quantitative composition, solubility in water at 293 K and magnetic moments were determined. IR spectra and powder diffraction patterns of the complexes prepared with general formula MC₇H₁₀O₄⋅nH₂O (n=0−2) were recorded and their thermal decomposition in air were studied. During heating the hydrated complexes of Mn(II),Co(II), Ni(II) and Cu(II) are dehydrated in one step and next all the anhydrous complexes decompose to oxides directly (Mn, Co, Zn) or with intermediate formation free metal (Ni,Cu) or oxocarbonates (Cd). The carboxylate groups in the complexes studied are bidentate. The magnetic moments for the paramagnetic complexes of Mn(II), Co(II), Ni(II) and Cu(II)attain values 5.62, 5.25, 2.91 and 1.41 M.B., respectively. This revised version was published online in August 2006 with corrections to the Cover Date.     

SYNTHESIS AND CHARACTERIZATION OF ANTI-2-FURAN CARBOXALDOXIME COMPLEXES WITH COBALT(II), COPPER(II & I) AND SILVER(I)

Abstract

The ligand, 2-furan carboxaldoxime exists in two geometrical isomeric forms: anti-(β-form) and syn-(α-form). Six different complexes of Co(II), Cu(II), Cu(I) and Ag(I) with anti-2-furan carboxaldoxime (FDH) have been prepared and characterized by elemental analysis, molecular weights, conductance studies, magnetic moments and infra-red spectral studies. These are [Co(FDH)₄Cl₂], [Co(FD)₂], [Cu(CH₃COO)₂ (FDH)]₂, [Cu(FD)(OH)]₂, Cu(FDH)₂ Cl and AgNO₃·2FDH. Under the similar conditions, syn- form does not form any complex with these metal ions. The complexes [Co(FDH)₄Cl₂] and [Co(FD)₂] are neutral, monomeric and para-magnetic (μ=4.88 and 4.52 BM respectively); the former may be considered as octahedral with FDH acting as monodentate, and the latter as tetrahedral with FD^? as a bidentate ligand. Both the Cu(II) complexes are neutral, dimeric, weakly para-magnetic (μ=0.44 and 0.28 BM respectively) with the bridging acetato groups in [Cu(CH₃ COO)₂ (FDH)]₂ and with bridging hydroxo groups in [Cu(FD)(OH)]₂. The Cu(I) complex may be polymeric, being insoluble in most solvents. The Ag(I) compound is cationic 1:1 electrolyte in nitrobenzene. In all these complexes the ligand functions as monodentate and/or bidentate, coordinating with furan oxygen and oxime oxygen in the latter case. The C[sbnd]O[sbnd]C stretching frequency of furan may be taken as the criterion for the denticity of this ligand which is observed at 1240 cm^?1 (in the free ligand). A shift to lower frequency is observed in the complex if the ligand acts as bidentate. However this frequency is not affected if the ligand acts as monodentate coordinating through the oxime oxygen atom. The ligand has been shown to be present in the ionized and/or unionized form in these complexes.     

Synthesis,Structural, Biological Evaluation,Molecular Docking and DFT Studies of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) Complexes bearing Heterocyclic Thiosemicarbazone ligand

A new ligand, 2‐aminonicotinaldehyde N‐methyl thiosemicarbazone (ANMTSC) and its metal complexes [Co(II) ( 1 ); Ni(II) ( 2 ); Cu(II) ( 3 ); Zn(II) ( 4 ); Cd(II) ( 5 ) or Hg(II) ( 6 )] were synthesized. The compounds were characterized by analytical methods and various spectroscopic (infrared, magnetic, thermal, ¹H, ¹³C NMR, electronic and ESR) tools. The structure of ANMTSC ligand was confirmed by single crystal X‐ray diffraction study. The spectral data of metal complexes indicate that the ligand acts as mononegative, bidentate coordination through imine nitrogen (N) and thiocarbonyl sulphur (S^?) atoms. The proposed geometries for complexes were octahedral ( 1 – 2 ), distorted octahedral ( 3 ) and tetrahedral ( 4 – 6 ). Computational details of theoretical calculations (DFT) of complexes have been discussed. The compounds were subjected to antimicrobial, antioxidant, antidiabetic, anticancer, ROS, studies and EGFR targeting molecular docking analysis. Complex 5 has shown excellent antibacterial activity and the complexes 2 and 5 have shown good antifungal activity. The complexes 1 and 4 displayed good antioxidant property with IC₅₀ values of 11.17 ± 1.92 μM and 10.79 ± 1.85 μM, respectively compared to standard. In addition, in vitro anticancer activity of the compounds was investigated against HeLa, MCF‐7, A549, IMR‐32 and HEK 293 cell lines. Among all the compounds, complex 4 was more effective against HeLa (IC₅₀ = 10.28 ± 0.69 μM), MCF‐7 (IC₅₀ = 9.80 ± 0.83 μM), A549 (IC₅₀ = 11.08 ± 0.57 μM) and IMR‐32 (10.41 ± 0.60 μM) exhibited superior anticancer activity [IC₅₀ = 9.80 ± 0.83 ( 4 ) and 9.91 ± 0.37 μM ( 1 )] against MCF‐7 compared with other complexes.     

Structural Relationships obtained from the Coordination of α‐Picolinamide to the (Iminodiacetato)copper(II) Chelate: Synthesis,Crystal Structure,and Properties of (α‐Picolinamide)(iminodiacetato)copper(II) Dihydrate

The stoichiometric reaction of copper(II) hydroxycarbonate, iminodiacetic acid (H₂IDA = HN(CH₂CO₂H)₂) and α‐picolinamide (pya) in water yields crystalline samples of (α‐picolinamide)(iminodiacetato)copper(II) dihydrate, [Cu(IDA)(pya)] · 2 H₂O ( 1 ). The compound was characterised by thermal (TG analysis with FT‐IR study of the evolved gasses), spectral (IR, electronic and ESR spectra), magnetic and single crystal X‐ray diffraction methods. It crystallises in the triclinic system, space group P1, a = 8.8737(4), b = 10.23203(5), c = 15.7167(11) Å, α = 77.61(1)°, β = 103.89(1)°, γ = 80.32(1)°, Z = 4, final R1 = 0.056. The asymmetric unit contains two crystallographic independent molecules but chemically very similar ones. The Cu^II atom exhibits a square base pyramidal coordination (type 4 + 1). pya acts as N,O‐bidentate ligand supplying two among the four closest donor atoms of the metal [averaged bond distances (Å): Cu–N = 1.982(2), Cu–O(amide) = 1.972(2)]. IDA plays a N,O,O′‐terdentate chelating role [averaged bond distances (Å): Cu–N = 2.004(3), Cu–O = 1.941(2) and Cu–O = 2.242(2)]. The coordinating behaviour of pya in 1 is discussed on the basis of its N,O‐bidentate chelating role and the preference of the ‘Cu‐iminodiacetato' moiety [Cu(IDA)] to link the N‐heterocyclic donor of pya in trans versus the Cu–N(IDA) bond. Consistently the ligand pya is able to impose a fac‐chelating configuration to IDA one around the copper(II) as previously has been reported to mixed‐ligand complexes having a 1/1/2 Cu^II/IDA/N(heterocyclic) donor ratio or a closely related 1/1/1/1 Cu^II/IDA/N(heterocyclic)/N(aliphatic) one.     

Coordination Behavior of N‐Donor Schiff Base Derived from 2‐Benzoylpyridine Toward Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), and Cr(III) Metal Ions: Synthesis,Spectroscopic and Thermal Studies,and Biological Activity

A new Schiff base was prepared from the reaction of 4,4′‐methylenedianiline with 2‐benzoylpyridine in 1:2 molar ratio, as well as its different metal chelates. The structures of the ligand and its metal complexes were studied by elemental analyses, spectroscopic methods (infrared [IR ], ultraviolet–visible [UV –vis], ¹H nuclear magnetic resonance [NMR ], electron spin resonance [ESR ]), magnetic moment measurements, and thermal studies. The ligand acts as tetradentate moiety in all complexes. Octahedral geometry was suggested for Mn(II ), Cu(II ), Cr(III ), and Zn(II ) chloride complexes and pentacoordinated structure and square planar geometry for Co(II ), Ni(II ), Cu(NO₃ )₂, CuBr₂ , and Pd(II ) complexes. ESR spectra of copper(II ) complexes ( 4 )–( 6 ) at room temperature display rhombic symmetry for complex ( 4 ) and axial type symmetry for complexes ( 5 ) and ( 6 ), indicating ground state for Cu(II ) complexes. The derivative thermogravimetric (DTG ) curves of the ligand and its metal complexes were analyzed by using the rate equation to calculate the thermodynamic and kinetic parameters, which indicated strong binding of the ligand with the metal ion in some complexes. Also, some of these compounds were screened to establish their potential as anticancer agents against the human hepatic cell line Hep‐G₂ . The obtained IC₅₀ value of the copper(II ) bromide complex (4.34 µg/mL ) is the highest among the compounds studied.     

Synthesis,characterization, DFT modeling and biological studies of new Co(II), Ni(II) and Cu(II) 4,6-bis(4-chlorophenyl)-2-amino-1,2-dihydropyridine-3-carbinitrile complexes

Three new metal complexes of 4,6-bis(4-chlorophenyl)-2-amino-1,2-dihydropyridine-3-carbinitrile (L) with Co(II), Ni(II) and Cu(II) were synthesized and characterized with physicochemical and spectroscopic techniques. The data suggest that (L) acts as a bidentate ligand bound to the divalent metal ions through amino N and carbinitrile N atoms having [M(L)₂(H₂O)₂]²⁺ formula (M = metal ions). The theoretical parameters, model structures, charges and molecular orbitals of all possible complexes have been determined using density functional theory. The energy gap of free ligand is ?E = 0.12565 eV, and this value is greater than energy gap of complexes, which indicates that the complexes are more reactive than free ligand. Also, ?E of Co(II) complex is lower than other complexes, which indicates that Co(II) complex is more reactive than Ni(II) and Cu(II) complexes. The antibacterial and antifungal activities of the ligand, metal salts and its complexes were tested against some microorganisms (bacteria and fungi). The complexes showed increased antibacterial and antifungal profile in comparison with the free ligand.     

Synthesis and spectral studies of new Co(II), Cu(II), and Ni(II) metal complexes with aromatic diamine

1,2-bis(p-aminophenoxy)ethane was obtained with reduction of 1,2-bis(p-nitrophenoxy)ethane and Pd/C as catalyst in hydrazine hydrate. Co(II), Cu(II), and Ni(II) complexes of aromatic bidentate diamine were prepared. The structure of the ligand and its complexes were characterized by IR, elemental analysis, magnetic susceptibility, conductivimetry, UV-Vis and ¹H NMR spectroscopy. The metal/ligand mole ratios were found to be 1:1. The general compositions of these complexes are found to be [CoLCl₂], [CuLCl₂], and [CoLCl₂]. The text was submitted by the authors in English.     

Fabrication of novel Fe (III), Co (II), Hg (II), and Pd (II) complexes based on water-soluble ligand (NaH2PH): structural characterization,cyclic voltammetric,powder X-ray diffraction,zeta potential,and biological studies

Sodium4-hydroxy-3-([2-picolinoylhydrazineylidene]methyl)benzenesulfonate (NaH₂PH) was synthesized as a novel water-soluble ligand, by the condensation of picolinohydrazide with sodium 3-formyl-4-hydroxybenzenesulfonate. The (NaH₂PH) ligand and its isolated Co (II), Fe (III), Hg (II), and Pd (II) complexes were analyzed by elemental analysis and characterized by spectroscopic (Fourier transform infrared spectroscopy, UV–visible, powder XRD, ¹H NMR,¹³C NMR, MS) and magnetic measurements. By comparing IR spectra of both ligand and the metal complexes, one can assume that the (NaH₂PH) ligand behaves as a bi-negative tetradentate (ONNO) in [Co (NaPH)(H₂O)₂].3H₂O, and a mono-negative tridentate (ONO) in [Fe (NaPH)Cl₂(H₂O)] complex, whereas in [Hg₂(NaPH)Cl₂(H₂O)] complex, (NaH₂PH) coordinates as a bi-negative pentadentate (ONNNO) ligand via deprotonated OH group of phenolic ring (C=N)_Py and (C=N*) coordinated to one of Hg (II) ion and the oxygen atom of enolic group and (C=N)_az group with the another Hg (II) ion. Moreover, (NaH₂PH) acts as bi-negative tridentate (ONO) ligand in [Pd (NaPH)(H₂O)].2H₂O complex. The geometries of complexes were suggested based on the UV–visible spectra, magnetic measurements and confirmed by applying discrete Fourier transform (DFT) optimization studies. The thermal fragmentation of both [Pd (NaPH)(H₂O)].2H₂O and [Co (NaPH)(H₂O)₂].3H₂O complexes was performed, and the kinetic and thermodynamic parameters were computed using the Coats–Redfern and Horowitz–Metzger methods. The redox behavior of divalent ions of cobalt and mercury were discussed by the cyclic voltammetry technique in the presence and absence of (NaH₂PH) ligand. Biological potencies of the ligand and its metal complexes were evaluated as antioxidants (ABTS and DPPH), anticancer, DNA, and antimicrobial (Staphylococcus aureus and Bacillus subtilis as Gram (+) bacteria, Escherichia coli and Pseudomonas aeruginosa as Gram (−) bacteria, and Candida albicans as fungi).     

Synthesis,Structural Characterization,and Antimicrobial Activities of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) Complexes of Triazole‐based Azodyes

The synthesis and characterization of new transition metal complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with 3‐(2‐hydroxynaph‐1‐ylazo)‐1,2,4‐triazole ( HL¹ ) and 3‐(2‐hydroxy‐3‐carboxynaph‐1‐ylazo)‐1,2,4‐triazole ( HL² ) have been carried out. Their structures were confirmed by elemental analyses, thermal analyses, spectral and magnetic data. The IR and ¹H NMR spectra indicated that HL¹ and HL² coordinated to the metal ions as bidentate monobasic ligands via the hydroxyl O and azo N atoms. The UV‐Vis, ESR spectra and magnetic moment data revealed the formation of octahedral complexes [Mn L¹ (AcO)(H₂O)₃] ( 1 ), [Co L¹ (AcO)(H₂O)₃]·H₂O ( 2 ), [Mn L² (AcO)(H₂O)₃] ( 6 ) and [Co L² (AcO)(H₂O)₃] ( 7 ), [Ni L¹ (AcO)(H₂O)] ( 3 ), [Zn L¹ (AcO)(H₂O)]·H₂O ( 5 ), [Ni L² (AcO)(H₂O)] ( 8 ), [Zn L² (AcO)(H₂O)]·10H₂O ( 10 ) have tetrahedral geometry, whereas [Cu L¹ (AcO)(H₂O)₂] ( 4 ) and [Cu L² (AcO)(H₂O)₂]·5H₂O ( 9 ) have square pyramidal geometry.. The mass spectra of the complexes under EI‐con‐ ditions showed the highest peaks corresponding to their molecular weights, based on the atomic weights of ⁵⁵Mn, ⁵⁹Co, ⁵⁸Ni, ⁶³Cu and ⁶⁴Zn isotopes; besides, other peaks containing other isotopes distribution of the metal. Kinetic and thermodynamic parameters of the thermal decomposition stages were computed from the thermal data using Coats‐Redfern method. HL² and complexes 6 – 10 were found to have moderate antimicrobial activities against Staphylococcus aureus (gram positive), Escherichia coli (gram negative) and Salmonella sp bacteria, and antifungal activity against Fusarium oxysporum, Aspergillus niger and Candida albicans. Also, in most cases, metallation increased the activity compared with the free ligand.     

Synthesis,characterization and anticancer studies of bis-(N-methyl-1-phenyldithiocarbamato) Cu(II), Zn(II), and Pt(II) complexes: single crystal X-ray structure of the copper complex

Abstract

Cu(II), Pt(II), and Zn(II) complexes of N-methyl-1-phenyldithiocarbamate were synthesized and characterized by FTIR, NMR, UV-visible spectroscopy and elemental analysis. The complexes were formulated as [Cu(L)₂], [Zn(L)₂] and [Pt(L)₂] (where L?=?N-methyl-1-phenyldithio­carbamate) in which two molecules of the ligands coordinate to the metal ions in a bidentate chelating fashion. This is confirmed by elemental analysis and the presence of strong single bands at 952, 951, and 955?cm^?1 for Cu(II), Pt(II), and Zn(II) complexes, respectively, in the FTIR spectra. The electronic spectra of Pt(II) and Cu(II) complexes are consistent with four-coordinate square planar geometry. Single crystal X-ray of [Cu(N-mpDTC)₂] confirmed square planar structural arrangement (CuS₄) in which the ligands are asymmetrically bonded to the Cu(II) ion building a centrosymmetric monomer entity. The S-Cu-S bite angle is 77.95° (3) whereas the intramolecular N–C bond length is 1.318 Å and trans S1¹-Cu-S1?=?S2¹-Cu-S2 is 180°, which are consistent with reported copper thiolates in square planar environment. In vitro antiproliferative activity of the complexes against three human cancer cell lines showed that the zinc complex has better activity compared to Cu and Pt complexes, with IC₅₀ values of 14.28, 22.74 and 20.10?μM against TK10, UACC62, and MC7 cell lines, respectively.