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A novel series of organotellurium compounds based on formazane derivatives with a general formula of ArTeBr34 and Ar2TeBr25 [Ar = 2-[{4-hydroxy-3-methoxyphenyl}{4-nitrophenyldiazenyl}methylene amino]-5-nitrophenyl] were synthesized by refluxing mercurated formazane derivative ArHgCl with TeBr4 in two different mole ratios of 1:1 and 2:1, respectively, in dry dioxane solvent under an argon atmosphere. Compounds ArTeBr3 and Ar2TeBr2 were then reduced by the action of an ethanolic solution of hydrazine hydrate to obtain Ar2Te26 and Ar2Te 7, respectively. The ligand properties of bis(2-[{4-hydroxy-3-methoxy phenyl}{4-nitrophenyl diazenyl}methylene amino]-5-nitrophenyl) telluride (7) were examined toward several metal ions through its reaction with K2PtCl4, PdCl2 · 2 H2O, K2PtCl6, RhCl3 · 3 H2O, CoCl3 · 6 H2O and NiCl2, respectively. These compounds were characterized by FTIR, UV-Vis,1H and 13C{1H} NMR spectroscopy and mass spectrometry as well as by elemental analysis, thermal analysis, magnetic susceptibility and molar conductivity. The identification of the synthesized complexes 8-13 proved that the complexes of Pt(II), Pd(II) and Ni(II) have square pyramidal geometries and are diamagnetic, while the complexes of Pt(IV), Rh(III) and Co(III) have octahedral shapes with the same magnetic behavior. The telluride 7 behaves as a neutral pentadentate ligand. [ABSTRACT FROM AUTHOR]

New series complexes of Cu(II), Ni(II), Zn (II) and Co(II) ions were derived from the novel thiosemicarbazone compound, (E)-4-methyl-3-nitro-N-(2-(1-(pyridin-2-yl)ethylidene)hydrazine1-carbonothioyl) benzamide (MNEC-H) ligand was prepared in three steps. The step one the reaction between acetyl pyridine with hydrazine hydrate at room temperature to obtain (E) - 2 -(1 -hydrazonoethyl)pyridine. The Second step 3-nitro 4- methy- benzoyl chloride was refluxed with potassium thiocyanate in acetonitrile solvent forming 3-nitro 4- methy- benzoyl isothiocyanate. The third step of the reaction is summarized by the refluxing the mixture of (E) - 2 -(1 -hydrazonoethyl) pyridine and 3-nitro 4- methy- benzoyl isothiocyanate in acetonitrile solvent to form the desired free ligand (MNEC-H). Two types of the element complexes were synthesized and investigated, the chloride as well as acetate compounds through employing different mole ratios 1:1 (L:M) and 2:1 (L:M) whereas L and M represent the (MNEC-H) ligand and metal salt respectively via using metal chloride and metal acetate salts to gaining [(MNECH)MCl]Cl and [(MNEC-H)2M] structures. The various available spectroscopies and techniques were used to characterize and confirm the formula of the free ligand (MNEC-H) and its element compounds. ¹HNMR, 13CNMR, IR, UV-vis, mass spectra, CHNS, magnetic effective moment, conductance values. The cyclic voltammetry of the prepared element complexes were recorded in DMSO solvent to investigate their redox behavior. The Cu(II) compounds showed quasi reversible process at the cathodic potential whereas the Co(II) and Ni(II) complexes displayed one irreversible system at the oxidative potential. All the employed techniques and measurements confirmed together that the chloride compounds arranged as tetrahedral four coordinated [(MNEC-H)MCl]Cl in neutral formula whereas the acetate compounds adopted octahedral six coordinated [(MNEC-H)2M] in neutral structure too. The Zn(II) chloride and acetate complexes were confirmed as diamagnetic species according to the effective magnetic data. While Cu(II), Ni(II), Co(II) and Zn(II) chloride and acetate compounds appeared as paramagnetic species. [ABSTRACT FROM AUTHOR]

Anew ligand N-((3,5-dichloropyridin-2-yl)carbamothioyl) pivalamide (L²) was synthesized by reaction of benzoyl isothiocyanate with 2-Amino-3,5- dichloropyridine by using acetonitrile as a solvent, The ligand was characterized by elemental analysis apparatus, FT-IR, 13C,¹H-NMR spectra, UV-Visible,, some transition metals complexes(Co, Ni, Cu, Zn ) of this ligand was prepared and characterized by FT-IR, UV-Visible spectra, conductivity measurements, magnetic susceptibility,From results the proposed molecular structure for these complexes as obtained, the following formula where M+2 = Co, Cu, Ni, Zn [M :L² ] [1 :1] Tetrahedral and [M:L² ] [1:2] Octahedral . The biological activity of the prepared compounds was measured and tested as antifungals against (Candida albicans, Aspergillus Niger) and using DMSO as a control solution The results showed that the prepared compounds possess antifungal activity at different concentrations, The effectiveness of the prepared ligands and their complexes with Zn(ll) ions were studied as anti-elevation of T3 and T4 thyroid hormones induced by thyroxine, and the results showed a decrease in T3 and T4 hormones after (20) days of taking these compounds. [ABSTRACT FROM AUTHOR]

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A novel set of Cobalt(II), Copper(II) and Nickel(II) complexes of ligands, (E)-2-(((2,5- difluorophenyl)imino) methyl)phenol (A), (E)-2,4-dibromo-1-((2-hydroxybenzylidene) amino) anthracene-9,10-dione (D) & (Z)-1-((1-([1,1'-biphenyl]-4-yl)-2-bromoethylidene) amino)-2,4-dibromo anthracene-9,10-dione (E) were synthesized and characterized. Their structures were investigated on the basis of CHN, conductance measurements and spectral studies (1HNMR & 13CNMR, FTinfrared and Electronic spectroscopies), cyclic voltammetry. It has observed from spectral and analytical studies that metal complexes have the composition of (ML2.X2) and one mole of ligand behaves as bidentate chelating agents around the corresponding metal ion. From solubility test, we obtained that metal complexes of ligands A, D and E had no ionic properties and dissolve partially in polar and slightly in nonpolar solvents. These results confirmed the behavior of metal complexes as weak electrolyte from their low value of molar conductivity. Conductance data and solubility test of the complexes enhanced them to be (1:2 M:L ratio). All data confirmed an octahedral geometry of these complexes and their structures as {[M (A, D or E)2(CH3COO)2], when M= Co or Ni} and {[Cu (A, D or E)2 Cl2]}. Cyclic voltammetry measurements were accomplished of Cobalt(II), Copper(II) and Nickel(II) complexes using Pt wire as counter electrode and Ag/AgNO3 as reference electrode and (Bu4N+PF6+) as supporting electrolyte. The result exhibit the irreversible process showing single one electron transfer process of Cobalt(II) and Nickel(II) complexes and unique quasi-reversible redox couple is attributed to Cu(II) complexes. [ABSTRACT FROM AUTHOR]

The synthesis of six N , N '-substituted thiourea ligands (L1a-L3b) was achieved in two steps. A corresponding extensive series of Cu(I), Cu(II), Ni(II) and Zn(II) complexes (1-24) with varying formulations were synthesised from these ligands by the reaction of a 1 : 1 or a 1 : 2 mixture of Cu(II), Ni(II) and Zn(II) perchlorate or chloride salts. Complexes 1-24 have been comprehensively characterised by mass spectrometry, elemental analysis, UV-vis., IR, and 1 H and 13 C{ 1 H} NMR spectroscopies where applicable. The X-ray crystal structures were obtained for eight examples: [(L1a) 2 Cu]ClO 4 (1), [(L1c) 2 Zn](ClO 4 ) 2 (4), [(L2a) 2 Cu]ClO 4 (6), [(L2c) 2 Ni](ClO 4 ) 2 (7), [(L1b) 2 Cu](ClO 4 ) (15), [(L1b)CuCl] (16), [(L4) 2 CuCl 2 ] (19) and [(L3b)CuClO 4 ] (21). These studies reveal that L1c and L2c represent ligands that have undergone cleavage during reaction with the metal salt; L4 represents an intramolecular rearrangement ( via a Hugershoff reaction) of L2b; and in most cases Cu(II) is reduced to Cu(I) during the ligand reaction. The X-ray crystal structures also reveal that 1, 4, 6, 15 and 16 are monometallic species in the solid state; that Cu(I) in 1, 6, 15 and 16 and Zn(II) in 4 are arranged in a distorted tetrahedral geometry; that Cu(I) in 21 adopts a trigonal planar geometry; and that in 7 and 19 the Ni(II) and Cu(II) centres, respectively, possess square planar geometry. Preliminary studies on the biological activity (using the Malaria Sybr Green I Fluorescence assay) of the thiourea containing complexes suggests that the d 10 complexes, and increased ligand stoichiometries, may afford higher potency.