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    Preparation, characterisation and redox properties of four new tetradentate salicylaldimines with their Cu(II) complexes
    (Sage Publications Ltd, 2006) Tas, Esref; Aslanoglu, Mehmet; Kilic, Ahmet; Kaplan, Omer; Temel, Hamdi
    Some new tetradentate salicylaldimine ligands of Schiff bases were synthesised by treating 3,5-di-tertbutyl-2-hydroxybenzaldehyde with 1,2-bis-(o-aminophenoxy)ethane, 1,4-bis-(o-aminophenoxy)butane, 1,4-bis(m-aminophenoxy)buthane and 1,4-bis-(p-aminophenoxy)butane. The compounds were characterised by IR, UV-vis, H-1 NMR, C-13 NMR, magnetic susceptibility measurements, elemental analysis, molar conductance (Am), thermogravimetric analysis (TGA) and cyclic voltammetry. The metal to ligand ratios of the Cu(II) complexes were found to be 1:1. The coordination of the novel tetradentate salicylaldimines appears to occur through the two azomethine nitrogens and two o-OH groups. Cyclic voltammetric studies showed that all of the C(II) complexes undergo quasi reversible one-electron transfer redox processes attributed the Cu(II)/Cu(I) couples in dimethylsufoxide. The electron donor affinity of copper(II) complexes increases in order Cu(L-4)>Cu(L-3)>Cu(L-2)>Cu(L-1).
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    Öğe
    Ru(II) with chelating containing N4-type donor quadridentate Pd-oxime metal complexes
    (Elsevier Science Sa, 2008) Kilic, Ahmet; Durap, Feyyaz; Aydemir, Murat; Baysal, Akin; Tas, Esref
    Five new metal complexes [ Pd( LH) 2] ( 1), [ Pd( L) 2Ru2( bpy) 4]( ClO4) 2 ( 2), [ Pd( L) 2Ru2( phen) 4]( ClO4) 2 ( 3), [ Pd( L) 2Ru2( dafo) 4]( ClO4) 2 ( 4) and [ Pd( L) 2Ru2( dcbpy) 4]( ClO4) 2 ( 5), ( where, L = ligand, bpy = 2,20- bipyridine, phen = 1,10- phenantroline, dafo = 4,5- diaza. uoren- 9- one and dcbpy = 3,30- dicarboxy- 2,20- bipyridine) have been isolated and characterized by UV - VIS, FT- IR, 1H NMR, magnetic susceptibility measurements, elemental analysis, molar conductivity, X- ray powder techniques, thermal analyses and their morphology studied by SEM measurements. IR spectra show that the ligand acts in a tetradentate manner and coordinates N4 donor groups of LH2 to PdII ion. The disappereance of H- bonding ( O-H center dot center dot center dot O) in the trinuclear RuII - PdII - RuII metal complexes, the RuII ion centered into the main oxime core by the coordination of the imino groups while the two RuII ions coordinate dianionic oxygen donors of the oxime groups and linked to the ligands of bpy, phen, dafo and dbpy. The X- powder results show that 1 metal complex is indicating crystalline nature, not amorphous nature. Whereas, the X- ray powder pattern of the ligand ( LH2) with 2, 3, 4 and 5 exhibited only broad humps, indicating its amorphous nature. The catalytic activity of three different complexes were tested in the Suzuki coupling reaction. The 1, 4 and 5 metal complexes catalyse Suzuki coupling reaction between phenylboronic acid and arylbromides affording biphenyls. Also, the thermal results shown that the most stable complex is 1 compound while the less stable is 4 compound. (c) 2008 Elsevier B. V. All rights reserved.
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    Öğe
    Synthesis and spectral characterization of macrocyclic NiII complexes derived from various diamines, NiII perchlorate and 1,4-bis(2-carboxyaldehydephenoxy)butane
    (Springer, 2007) Ilhan, Salih; Temel, Hamdi; Kilic, Ahmet; Tas, Esref
    Six new macrocyclic complexes were synthesized by reaction of 1,4-bis(2-carboxyaldehyde phenoxy)butane with various diamines. Then, their nickel(II) perchlorate complexes were synthesized by the template effect by reaction of 1,4-bis(2-carboxyaldehyde phenoxy)butane, Ni(ClO4)(2) center dot 6H(2)O and various diamines. The metal-to-ligand ratio of Ni-II metal complexes was found to be 1:1. The compounds are coordinated to the central metal as tetradentate O2N2 ligands The Ni-II complexes are proposed to exhibit tetrahedral geometry. Ni-II metal complexes are 1:2 electrolytes as shown by their molar conductivities (Lambda(M)) in DMF (dimethyl formamide) at 10(-3) M. The structure of Ni-II metal complexes is proposed from elemental analysis, f.t.-i.r., u.v.-vis., magnetic susceptibility measurements, molar conductivity measurements and mass spectra.
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    Synthesis, spectral characterization and electrochemical properties of new vic-dioxime complexes bearing carboxylate
    (Springer, 2006) Kilic, Ahmet; Tas, Esref; Gumgum, Bahattin; Yilmaz, Ismail
    Three new vic-dioxime ligands, [N-(ethyl-4-amino-1-piperidine carboxylate)-phenylglyoxime ((LH2)-H-1), N-(ethyl-4-amino-1-piperidine carboxylate)-glyoxime (L(2)pH(2)), and N,N'-bis(ethyl-4-amino-1-piperidine carboxylate)-glyoxime ((LH2)-H-3)], and their Co(II) with Cu(II) metal complexes, were synthesized for the first time. Mononuclear complexes of these ligands with a 1:2 metal-ligand ratio were prepared with Co(II) and Cu(II) salts. The BF2+-capped Co(II) and mononuclear complexes of the vic-dioxime were prepared for [Co(L-1 center dot BF2)(2)] and [Co(L-2 center dot BF2)(2)]. The ligands act in a polydentate fashion bonding through nitrogen atoms in the presence of a base, as do most vic-dioximes. The cobalt(II) and copper(II) complexes are non-electrolytes as shown by their molar conductivities (Lambda(M)) in DMF. The structures of the ligands and complexes were determined by elemental analyses, FT-i.r., u.v.-vis., H-1- and C-13-n.m.r. spectra, magnetic susceptibility measurements, and molar conductivity. The comparative electrochemical studies show that the stabilities of the reduced or oxidized species and the electrode potentials of the complexes are affected by the substituents attached on the oxime moieties of the complexes.
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    The synthesis, spectroscopic and voltametric studies of new metal complexes containing three different vic-dioximes
    (Taylor & Francis Ltd, 2007) Kilic, Ahmet; Tas, Esref; Gumgum, Bahattin; Yilmaz, Ismail
    The synthesis, spectroscopic, and redox properties of some metal complexes with three novel vic-dioxime ligands, N-(1-(2-aminoethyl) piperazine)-phenylglyoxime (L1H2), N-(1-(2-aminoethyl) piperazine)-glyoxime (L2H2), and N, N'-bis(1-(2-aminoethyl) piperazine)-glyoxime (L3H2)], prepared from different glyoxime and 1-(2-aminoethyl) piperazine are reported. The structure of these vic-dioximes have been determined as the anti-form according to H-1 NMR, C-13 NMR, and FT-IR data. The metal to ligand ratios of Co(II), Ni(II), and Cu(II) complexes were found to be 1:2. The Cu(II) complexes of these ligands are proposed to be square planar and Ni(II) complexes of these ligands are proposed to be square planar or octahedral, while the Co(II) complexes are proposed to be octahedral with water molecules as axial ligands. Ni(II), Co(II), and Cu(II) metal complexes are non-electrolytes as shown by their molar conductivities (Lambda(M)) in DMF (dimethyl formamide) at 10(-3) M. The structure of ligands and their complexes is proposed from elemental analysis, FT-IR, UV-VIS, H-1 NMR, C-13 NMR, magnetic susceptibility measurements, and molar conductivity measurements. The cyclic voltammetric measurements of the mononuclear complexes provide an understanding of the electrochemical behaviour of the reduced or oxidized species in DMSO solution.