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Öğe Synthesis of new boron complexes: application to transfer hydrogenation of acetophenone derivatives(Wiley-Blackwell, 2011) Kılıç, Ahmet; Kayan, Cezmi; Aydemir, Murat; Durap, Feyyaz; Durgun, Mustafa; Baysal, Akın; Taş, Eşref; Gümgüm, Bahattin; 0000-0001-7294-6792; 0000-0003-0899-1948; 0000-0003-3012-7582; 0000-0001-9073-4339; 0000-0001-5700-8546Two new boron complexes were synthesized from N-[3-(methylmercapto)aniline]-3,5-di-tert-butylsalicylaldimine (LH) with boron reagent BPh3 or BF3 center dot Et2O. These boron complexes are stable and easily soluble in protic solvents such as ethanol (C2H5OH) but hardly soluble in nonprotic solvents such as chloroform (CHCl3), dichloromethane (CH2Cl2) and tetrahydrofuran (THF). All new boron complexes have been fully characterized by both analytical and spectroscopic methods. The catalytic activities of complexes [LBPh2], 2, and [LBF2], 3, in the transfer hydrogenation of acetophenone derivatives were tested. Stable boron complexes were found to be efficient catalysts in the transfer hydrogenation of aromatic ketones in good conversions up to 99% in the presence of iso-PrOH/KOH. Copyright (C) 2011 John Wiley & Sons, Ltd.Öğe Synthesis, spectroscopic and electrochemical investigations of two vic-dioximes and their mononuclear Ni(II), Cu(II) and Co(II) metal complexes containing morpholine group(Wiley-V C H Verlag Gmbh, 2006) Kılıç, Ahmet; Taş, Eşref; Gümgüm, Bahattin; Yımaz, İsmail; 0000-0001-9073-4339; 0000-0002-5046-7456Two vic-dioxime ligands (LxH2) containing morpholine group have been synthesized from 4-[2-(dimethylaminoethyl)] morpholine with anti-phenylchloroglyoxime or anti-monochloroglyoxime in absolute THF at -15 degrees C. Reaction of two vic-dioxime ligands with MCl2 center dot nH(2)O (M: Ni, Cu or Co and n=2 or 6) salts in 1 : 2 molar ratio afforded metal complexes of type [M(LxH)(2)] or [M(LxH)(2)center dot 2H(2)O]. All of metal complexes are non-electrolytes as shown by their molar conductivities (Lambda(m)) in DMF (dimethyl formamide) at 10(-3) mol.L-1. Structures of the ligands and metal complexes have been solved by elemental analyses, FT-IR, UV-Vis, H-1 NMR and C-13 NMR, magnetic susceptibility measurements, molar conductivity measurements. Furthermore, redox properties of the metal complexes were investigated by cyclic voltammetry.Öğe Synthesis, spectroscopic and electrochemical studies of novel transition metal complexes with quadridentate Schiff base(Wiley-V C H Verlag Gmbh, 2006) Temel, Hamdi; İlhan, Salih; Aslanoğlu, Mehmet; Kılıç, Ahmet; Taş, EşrefA novel quadridentate, N2O2 type Schiff base, synthesized from 1,4-bis-(o-aminophenoxy)butane and 2-hydroxynaphthalin-1-carbaldehyde, forms stable complexes with transition metal ions such as Co(II), Cu(II) and Ni(II) in DMF. Microanalytical data, elemental analysis, magnetic measurements, UV-visible and IR-spectra as well as conductance measurements were used to confirm the structures: Electrochemical measurements show that metal complexes undergo quasi-reversible one-electron redox processes. The voltammetric results also revealed that the CuL complex has the highest electron transfer rate indicating that both the Cu(II) and Cu(I) forms appear in a similar planar configuration, so the electron transfer does not require larger reorganization of the complex.Öğe Synthesis, spectroscopic, thermal analysis and in vitro cytotoxicity, anticholinesterase and antioxidant activities of new Co(II), Ni(II), Cu(II), Zn(II), and Ru(III) complexes of pyrazolone-based Schiff base ligand(Elsevier B.V., 2023) Çakmak, Reşit; Ay, Burak; Çınar, Ercan; Başaran, Eyüp; Akkoç, Senem; Boğa, Mehmet; Taş, EşrefMetal-based drugs have gained significant importance in medicine in recent years. In this research, a series of new Co(II), Ni (II), Cu (II), Zn(II), and Ru(III) complexes of a Schiff base ligand, (1,5-dimethyl-4-((1-(3-nitrophenyl)ethylidene) amino)-2-phenyl-1,2-dihydro-3H-pyrazol-3-one), were prepared for the first time in excellent yields, and characterized by elemental analysis, FT-IR, 1 H NMR, 13C NMR, ICP-OES, and thermal analysis. The in vitro antiproliferative, anticholinesterase, and antioxidant properties of complexes 1–5 were evaluated. The cytotoxic effects of complexes 1–5 on the viability of colon cancer (DLD-1), breast cancer (MDA-MB-231), and healthy lung (Wl-38) cell lines were investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method in vitro. The anticancer activities of the ligand and its metal complexes were lower than those of the reference drug, cisplatin. In anticholinesterase activity studies, complex 4 (88.46±0.45% inhibition) in butyrylcholinesterase (BChE) assay showed a higher inhibitory effect than the standard compound galanthamine with 78.14±0.55% inhibition. In antioxidant assays, some complexes showed higher antioxidant activities than standard antioxidant butylated hydroxytoluene (BHT). Among the prepared complexes, complex (4) (IC50=5.91±0.17 µM) in ABTS assay showed the highest antioxidant activity compared to BHT (IC50=16.19 ±0.17 µM). Also, this complex (IC50=10.17±0.36 µM) showed the best antioxidant activity in CUPRAC assay compared to BHT (IC50=39.37±0.12 µM).Öğe Three new vic-dioxime ligands: Synthesis, characterization, spectroscopy, and redox properties of their mononuc ear nickel(II) complexes(John Wiley & Sons Inc, 2007) Kılıç, Ahmet; Taş, Eşref; Gümgüm, Bahattin; Yılmaz, İsmail; 0000-0001-9073-4339; 0000-0001-9410-2945; 0000-0002-5046-7456Nickel(II) complexes with three new vic-dioxime reagents, N-(ethyl-4-amino-l-piperidine carboxylate)phenylglyoxime (L2H2), N-(ethyl-4-amino- 1-piperidine carboxylate)glyoxime (L2H2) and N,N'-bis(ethyl-4-amino-1-piperidine carboxylate)glyoxime (L3H2), have been prepared. Mononuclear nickel(II) complexes with a metal/ligand ratio of 1:2 were prepared using Ni(II) salt. All these nickel(II) complexes are nonelectrolytes as shown by their molar conductivities (Lambda(M)) in DMF solution at 10(-3) M concentration. The ligands are soluble in common solvents such as DMSO, DMF, CHCl3, and C2H5OH. The ligands and their Ni(II) complexes were characterized by elemental analyses, FT-IR, UV-visible, H-1 NMR, 13 C NMR, magnetic susceptibility measurements, cyclic voltammetry, and molar conductivities (Am). The cyclic voltammetric measurements show that [Ni(L1H)(2)] and [Ni(L2H)(2)]complexes exhibit almost similar electrochemical behavior, with two reduction and two oxidation processes based on either metals or oxime moities, while [Ni(L3H)(2)center dot 2H(2)O] complex displays irreversible, with one reduction and one oxidation processes based on oxime moity. This main difference could be attributed to the highly polarized [Ni(L3H)(2)center dot 2H(2)O] complex that has four carboxylate groups attached to piperidine on the oxime moieties. (c) 2007 Wiley Periodicals, Inc.
