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Öğe Preparation, spectral studies, theoretical, electrochemical and antibacterial investigation of a new Schiff base and its some metal complexes(Elsevier, 2014-10-05) İlhan, Salih; Baykara, Hacı; Seyitoğlu, Mehmet Salih; Levent, Abdulkadir; Özdemir, Sadin; Dündar, Abdurrahman; Öztomsuk, Abdussamet; Cornejo, MauricioA new Schiff base ligand, 1,6-Bis(2-(5-bromo-2-hydroxybenzylideneamino)-4-chlorophenoxy)hexane was synthesized. Some Schiff metal complexes of the new Schiff base were prepared by the reaction of some metal salts and the Schiff base. The complexes are non-electrolytes as shown by their molar conductivities (ΛM). The structures of metal complexes are proposed from elemental analysis, FT-IR, UV–vis, magnetic susceptibility measurements, molar conductivity measurements, mass spectra and thermal gravimetric analysis. In addition theoretical 1H NMR, HOMO–LUMO studies of the ligand; antimicrobial and cyclic voltammetric studies of the compounds were also carried out. In this study antioxidant and antibacterial activities of the compounds were examined via in vitro methods.Öğe Synthesis and characterization of a new difunctional ligand and its metal complexes: An experimental, theoretical, cyclic voltammetric, and antimicrobial study(Taylor & Francis, 2015-07-29) Baykara, Hacı; İlhan, Salih; Öztomsuk, Abdussamet; Seyitoğlu, Mehmet Salih; Levent, Abdulkadir; Okumuş, Veysi; Dündar, AbdurrahmanA new difunctional Schiff base ligand and its some metal complexes were synthesized. The compounds were characterized by elemental analysis, 1H-NMR, 13C-NMR, FT-IR, UV-VIS, magnetic susceptibility measurements, molar conductivity measurements, and thermal gravimetric analysis techniques. Additionally, DPPH scavenging, metal chelating and antibacterial activity of compounds were examined via in vitro methods. The lowest DPPH scavenging activity observed by Co(II) as 36.28% and highest was ligand as 52.00%. A cyclic voltammetric study was also carried out to determine redox potentials of the compounds. Some theoretical studies such as 1H-NMR, HOMO-LUMO, and mapped electron density of the ligand were also carried out successfully.Öğe Voltammetric behavior of benzo[a]pyrene at boron-doped diamond electrode: A study of its determination by adsorptive transfer stripping voltammetry based on the enhancement effect of anionic surfactant, sodium dodecylsulfate(Elsevier, 2011-07-15) Yardım, Yavuz; Keskin, Ertuğrul; Levent, Abdulkadir; Şentürk, ZühreBenzo[a]pyrene (BaP), a member of the polycyclic aromatic hydrocarbon (PAH) class, is one of the most potent PAH carcinogens. The electrochemical oxidation of BaP was first studied by cyclic voltammetry at the boron-doped diamond electrode in non-aqueous solvent (dimethylsulphoxide with lithium perchlorate). The compound was irreversibly oxidized in a single step at high positive potential, resulting in the well-resolved formation of a couple with a reduction and re-oxidation wave at much lower potentials. Special attention was given to the use of adsorptive stripping voltammetry together with a medium exchange procedure in aqueous and aqueous/surfactant solutions over the pH range of 2.0–8.0. The technique in aqueous solutions had little value in practice because of too small oxidation peak current. This problem was solved when surfactants were added into the sample solution, by which the oxidation peak currents of BaP were found enhanced dramatically. The employed surfactants were sodium dodecylsulfate (anionic, SDS), cetyltrimethylammonium bromide (cationic, CTAB) and Tween 80 (non-ionic). Using square-wave stripping mode, the compound yielded a well-defined voltammetric response in Britton–Robinson buffer, pH 2.0 containing 2.5 × 10−4 M SDS at +1.07 V (vs. Ag/AgCl) (after 120 s accumulation at +0.10 V). The process could be used to determine BaP in the concentration range of 16–200 nM (4.04–50.46 ng mL−1), with a detection limit of 2.86 nM (0.72 ng mL−1). This method was also applied to determine BaP in model water sample prepared by adding its different concentrations into tap water.Öğe Synthesis and characterization of 1,2-bis(2-(5-bromo-2-hydroxybenzilidenamino)-4-chlorophenoxy)ethane and its metal complexes: An experimental, theoretical, electrochemical, antioxidant and antibacterial study(Elsevier, 2014-01-24) İlhan, Salih; Baykara, Hacı; Öztomsuk, Abdussamet; Levent, Abdulkadir; Seyitoğlu, Mehmet Salih; Özdemir, SadinA new Schiff base ligand was synthesized by reaction of 5-bromosalicylaldehyde with 1,2-bis(4-chloro-2-aminophenoxy)ethane. Then the Schiff base complexes were synthesized by the reaction of metal salts and the novel Schiff base. The molar conductivity properties of the complexes were studied and found out that the complexes are nonelectrolytes. The structures of the ligand and its metal complexes were characterized by elemental analysis, FT-IR, UV–VIS, magnetic susceptibility measurements, molar conductivity measurements, and thermal gravimetric analysis. In addition antioxidant, theoretical NMR studies and cyclic voltammetry of the complexes were done. Two methods namely metal chelating activity and diphenylpicrylhydrazyl (DPPH) radical scavenging method were used to determine the antioxidant activity, and antibacterial properties of the compounds were also studied.
