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Öğe (4,9-Dimethyl-9H-carbazol-3-yl)methanol(2014) Öncüoğlu, Serkan; Dilek, Nefise; Ergün, Yavuz; Hökelek, TuncerIn the title compound, C15H15NO, the carbazole skeleton includes a methanol group at the 3-position. The indole ring system is almost planar [maximum deviation = 0.045 (2) Å]. In the crystal, O - H?O hydrogen bonds link the molecules into zigzag chains along the b-axis direction. There are weak C - H?? interactions within the chains and linking neighbouring chains forming sheets lying parallel to (001).Öğe 4-Butoxy-N'-[1-(4-methylphenyl)ethylidene]benzohydrazide(2012) Dilek, Nefise; Güneş, Bilal; Gup, RamazanThe molecule of the title compound, C20H24N 2O2, exists in a trans conformation with respect to the C=N bond. The dihedral angle between the benzene rings is 79.0 (1)°. In the crystal, N - H?O hydrogen bonds link the molecules into chains propagating in [001]. Two weak C - H?O interactions also occur.Öğe 4-Hydroxy-N'-[(1E)-1-(4-methylphenyl)ethylidene]benzohydrazide: Synthesis, crystal structure, and spectroscopic studies(MAIK NAUKA/INTERPERIODICA/SPRINGER, 2013) Dilek, Nefise; Güneş, Bilal; Gökçe, Cansu; Güp, RamazanThe titled compound has been synthesized by reaction of 4'-methylacetophenon with 4-hydrox-ybenzohydrazide in presence of catalytic amount of glacial acetic acid. The compound is characterized by elemental analysis, IR, H-1 NMR, C-13 NMR and UV-visible spectra. The crystal structure was determined by X-ray diffraction method. Both X-ray data and NMR spectra indicate that the molecule exists in a trans configuration with respect to the C=N bond. The observation of strong nu(C=O) peak in IR spectra of the aroylhydrazone compound suggests that it is in keto form in solid state. X-ray diffraction results confirm this suggestion. In the crystal structure, there are N-H...O and O-H...O hydrogen bonds and weak C-H...pi interaction.Öğe Catena-Poly[[aquabis(4-formylbenzoato-K 2 O 1 ,O 1' )cadmium]-µ-pyrazine-K 2 N:N'](2014) Çelik, Fatih; Dilek, Nefise; Çaylak Delibaş, Nagihan; Necefoglu, Hacali; Hökelek, TuncerThe polymeric title compound, [Cd(C8H5O3)2(C4H4N2)(H2O)] n , contains two 4-formylbenzoate (FB) anions, one pyrazine molecule and one coordinating water molecule; the FB anions act as bidentate ligands. The O atom, the aldehyde H atom and the benzene ring of one of the FB anions are disordered over two positions. The O atoms were freely refined [refined occupancy ratio 0.79(2):0.21(2)], while the aldehyde H atoms and the benzene ring atoms were refined with fixed occupancy ratios of 0.8:0.2 and 0.5:0.5, respectively. In the ordered FB anion, the carboxylate group is twisted away from the attached benzene ring (A) by 22.7(8)°. In the disordered FB anion, the corresponding angles are 15.6(10) and 11.4(11)° for rings B and B', respectively. Benzene rings A and B are oriented at a dihedral angle of 24.2(7), A and B' at 43.0(8)°. The pyrazine ring makes dihedral angles of 67.5(4), 89.6(7) and 86.2(7)°, respectively, with benzene rings A, B and B'. The pyrazine ligands bridge the Cd II cations, forming polymeric chains running along the b-axis direction. In the crystal, O - Hwater Ocarboxylate hydrogen bonds link adjacent chains into layers parallel to the bc plane. These layers are linked via C - Hpyrazine Oformyl hydrogen bonds, forming a three-dimensional network. ?-? interactions [centroid-centroid distances = 3.870(11)-3.951(5)Å] further stabilize the crystal structure. There is also a weak C - H? interaction present. © Çelik et al. 2014.Öğe Catena-Poly[[diaquabis(4-formylbenzoato-KO 1)copper(II)]- µ-pyrazine-K2 N:N'](2014) Çelik, Fatih; Dilek, Nefise; Çaylak Delibaş, Nagihan; Necefoğlu, Hacali; Hökelek, TuncerIn the title polymeric compound, [Cu(C8H5O 3)2(C4H4N2)(H2O) 2]n , the CuII atom is located on a twofold rotation axis and has a slightly distorted octahedral coordination sphere. In the equatorial plane, it is coordinated by two carboxylate O atoms of two symmetry-related monodentate formylbenzoate anions and by two N atoms of the bridging pyrazine ligand, which is bisected by the twofold rotation axis. The axial positions are occupied by two O atoms of the coordinating water molecules. In the formylbenzoate anion, the carboxylate group is twisted away from the attached benzene ring by 6.2(2)°, while the benzene and pyrazine rings are oriented at a dihedral angle of 68.91(8)°. The pyrazine ligands bridge the Cu II cations, forming polymeric chains running along the b-axis direction. Strong intramolecular O-H?O hydrogen bonds link the water molecules to the carboxylate O atoms. In the crystal, O-Hwater?Owater hydrogen bonds link adjacent chains into layers parallel to the bc plane. The layers are linked via C-Hpyrazine?Oformyl hydrogen bonds, forming a three-dimensional network. There are also weak C-H?? interactions present.Öğe Catena-Poly[[diaquabis(4-formylbenzoato-KO1)nickel(II)]- µ-pyrazine-K2 N:N'](2014) Çelik, Fatih; Dilek, Nefise; Çaylak Delibaş, Nagihan; Necefoğlu, Hacali; Hökelek, TuncerIn the title polymeric compound, [Ni(C8H5O3)2(C4H4N2)(H2O)2] n , the NiII atom is located on a twofold rotation axis and has a slightly distorted octahedral coordination sphere. In the equatorial plane, it is coordinated by two carboxylate O atoms of two symmetry-related monodentate formylbenzoate anions and by two N atoms of the bridging pyrazine ligand, which is bisected by the twofold rotation axis. The axial positions are occupied by two O atoms of the coordinating water molecules. In the formylbenzoate anion, the carboxylate group is twisted away from the attached benzene ring by 7.0(6)°, while the benzene and pyrazine rings are oriented at a dihedral angle of 66.2(3)°. The pyrazine ligands bridge the NiII cations, forming polymeric chains running along the b-axis direction. Intramolecular O - HO hydrogen bonds link the water ligands to the carboxylate O atoms. In the crystal, water-water O - HO hydrogen bonds link adjacent chains into layers parallel to the bc plane. Pyrazine-formyl C - HO hydrogen bonds link the layers, forming a three-dimensional network. There are also weak C - H? interactions present. The title compound is isotypic with the copper(II) complex [Çelik et al. (2014a). Acta Cryst. E70, m4-m5]. © Çelik et al. 2014.Öğe Crystal structure of bis(isothiocyanato)[2,6-diacetylpyridine bis(4-hydroxybenzoylhydrazone)]Fe(III) chloride bis(dimethylformamide) solvate(Maik Nauka/Interperiodica/Springer, 2013) Dilek, Nefise; Güneş, Bilal; Büyükgüngör, Orhan; Güp, RamazanThe crystal structure of title compound (Fe[(C25H21N7O4S2)] center dot 4(C3NOH7), where C3NOH7 is dimethylformamide, DMF) was determined by the X-ray diffraction method. This compound crystallizes in the monoclinic C2/c space group, Z = 4. Unit cell parameters are: a = 13.6080(5), b = 17.6375(7), c = 19.5571(6) , beta = 108.753(2)A degrees. The N-H...O and O-H...O interactions stabilize the molecules in the lattice. The structure contains also the solvent dimethylformamide molecules, which are connected with intermoleculer hydrogen bond. The O atoms of DMF molecules take place as acceptor atoms.Öğe DFT calculations, spectroscopy and antioxidant activity studieson (E)-2-nitro-4-[(phenylimino)methyl]phenol(Pergamon-Elsevıer Scıence Ltd, 2015) Temel, Ersin; Alaşalvar, Can; Gökçe, Halil; Güder, Aytaç; Albayrak, Çiğdem; Bingöl Alpaslan, Yelda; Alpaslan, Gökhan; Dilek, NefiseWe have reported synthesis and characterization of (E)-2-nitro-4-[(phenylimino)methyl]phenol by using X-ray crystallographic method, FT-IR and UV vis spectroscopies and density functional theory (DFT). Optimized geometry and vibrational frequencies of the title compound in the ground state have been computed by using B3LYP with the 6-311G+(d,p) basis set. HOMO LUMO energy gap, Non-linear optical properties and NBO analysis of the compound are performed at B3LYP/6-311G+(d,p) level. Additionally, as remarkable properties, antioxidant activity of the title compound (CMPD) has been determined by using different antioxidant test methods i.e. ferric reducing antioxidant power (FRAP), hydrogen peroxide scavenging (HPSA), free radical scavenging (FRSA) and ferrous ion chelating activities (FICA). When compared with standards (BHA, BHT, and alpha-tocopherol), we have concluded that CPMD has effective FRAP, HPSA, FRSA and FICA. (C) 2014 Elsevier B.V. All rights reserved.Öğe Ethyl 4,9-dimethyl-9H-carbazole-3- carboxylate(Acta Crystallographica Section E, 2014) Öncüoğlu, Serkan; Dilek, Nefise; Çaylak Delibaş, Nagihan; Ergün, Yavuz; Hökelek, Tuncer[Abstract Not Availablr]Öğe New macrocyclic schiff base complexes incorporating a homopiperazine unit: Synthesis of some Co(II), Ni(II),Cu(II) and Zn(II) complexes and crystal structure and theoretical studies(Elsevier Science Bv, 2016) Keypour, Hassan; Rezaeivala, Majid; Ramezani-Aktij, Ameneh; Bayat, Mehdi; Dilek, Nefise; Ünver, HuseyinA new macrocyclic Schiff base ligand, L, was synthesized by condensation reaction of 1,4-bis(2-formylphenyl)homopiperazine and 1,4-diaminobutane in acetonitrile. The Schiff base ligand was characterized by using elemental analyses, FT-IR, H-1, C-13 NMR and mass spectroscopic techniques. The metal (II) complexes [ML], were synthesized from the reaction of MCl2 center dot nH(2)O (M: Co, Ni, Cu and Zn) with Schiff base ligand, L and characterized by elemental analyses and FT-IR. X-ray crystal structure of [CoLCl](+) distorted square pyramidal geometry with an N4Cl core, arising from coordination by the four donor nitrogen atoms from the macrocyclic framework and one Cl atom. It crystallizes triclinic space group, P-1 with a = 7.1777(1) angstrom, b = 11.0357 (2) angstrom, c = 15.1520(2) angstrom, V = 1183.14(3), Z = 2, D-c = 1.556 g cm(-3), mu (MoK alpha) = 0.156 mm(-1). Also, the bonding situation between the [MCl](+) and Ligand (L) fragments in [MLCl]ClO4 (M = Co(II), Ni(II), Cu(II), Zn(II)) complexes were carried out by energy-decomposition analysis (EDA). The results showed that there is an increasing trend in the case of Delta E-elstat of the complexes by changing the M from Co(II) to Zn(II). (C) 2016 Elsevier B.V. All rights reserved.Öğe Probing the effect of arm length and inter- and intramolecular interactions in the formation of Cu(II) complexes of Schiff base ligands derived from some unsymmetrical tripodal amines(ROYAL SOC CHEMISTRY, 2015) Keypour, Hassan; Shayesteh, Maryam; Salehzadeh, Sadegh; Dhers, Sebastien; Maleki, Farahnaz; Unver, Huseyin; Dilek, NefiseThe syntheses of two previously known, 2-((2-aminoethyl)(pyridin-2-ylmethyl) amino) ethanol (1) and 2-((3-aminopropyl)(pyridin-2-ylmethyl) amino) ethanol (2), and four new unsymmetrical N-capped tripodal amines, 2-((4-aminobutyl)(pyridin-2-ylmethyl) amino) ethanol (3), 3-((2-aminoethyl)(pyridin-2-ylmethyl)amino)-propan-1-ol (4), 3-((3-aminopropyl)(pyridin-2-ylmethyl) amino) propan-1-ol (5) and 3-((4-aminobutyl)(pyridin-2-ylmethyl) amino) propan-1-ol (6), are reported. The ligands (3-4) feature a longer arm, 3-hydroxypropyl or butylamino, than in the analogues previously employed (2-hydroxyethyl arm, ethylamino-arm or propylamino-arm in 1 and 2). All six tripodal amines, 1-6, are equipped with a 2-methylpyridyl-arm and either an ethylamino-arm (1 and 4), propylamino-arm (2 and 5) or butylamino-arm (3 and 6). The new amines, 3-6, have been employed in one pot condensation reactions with 2-hydroxy-1-naphthaldehyde and salicylaldehyde (and its derivatives) in the presence of Cu(II) metal ions to generate a series of new mononuclear complexes, [(MLaldi)-L-parallel to](ClO4) as well as new dinuclear complexes [(CuLaldi)-L-parallel to](2)(ClO4)(2) of new ligands L-aldi. Four monomeric complexes and one dimeric complex have been characterised by single crystal X-ray diffraction, revealing a distorted square-pyramidal copper(II) ion. A general comparison between these structures shows that the number and types of chelate ring sequences around the metal ions are important in the formation of structures. Theoretical studies show that the 3-hydroxypropyl arm in these complexes is a weak coordinating group and it can readily be removed from the coordination sphere of metal ions, resulting in a dimerised four coordinate complex. Calculations show that the interaction between the two monomeric fragments is very weak.Öğe Seven coordinated cobalt(II) complexes with 2,6-diacetylpyridine bis(4-acylhydrazone) ligands: Synthesis, characterization, DNA-binding and nuclease activity(Elsevier Science Sa, 2015) Gökçe, Cansu; Dilek, Nefise; Gup, RamazanA new series of pentadentate 2,6-diacetylpyridine bis(4-acylhydrazone)s (H2L1 and H2L2) based seven-coordinated cobalt(II) complexes, [Co(L-n)X-2] (n = 1 and X = DMF for (1); n = 2 and X = H2O for (2)); [Co(H2Ln)Y-2] (n = 1 or 2; Y = N-3 or NCS ), has been synthesized and characterized by using spectroscopic techniques. Single crystal X-ray study of [Co(L-1)(DMF)(2)] (1) complex exhibits pentagonal-bipyramidal coordination geometry where the pentadentate N3O2 ligand in the equatorial plane of the bipyramid and two dimethylformamide molecules in the axial area. Interaction of the cobalt(II) complexes with CT DNA has been investigated by absorption titration method and viscosity measurements which reveal that the cobalt(II) complexes could bind with CT DNA through intercalation. Cleavage activity of the complexes (1) and (2) with pBR 322 plasmid DNA was evaluated by agarose gel electrophoresis demonstrating that the ability of the complexes to cleave the pBR 322 plasmid DNA via oxidative pathway, possibly due to the involvement of a diffusible hydroxyl radical mechanism in presence and absence of an oxidative agent. The nuclease activity of the Co(II) complexes has strong dependence on the concentration of complex and reaction time, both in presence and absence of hydrogen peroxide.Öğe Synthesis and characterization of Co(II), Ni(II), Cu(II) and Zn(II) complexes with a new homopiperazine macrocyclic Schiff base ligand(Elsevier, 2015) Keypour, Hassan; Rezaeivala, Majid; Mirzaei-Monsef, Misagh; Sayın, Koray; Dilek, Nefise; Ünver, HüseyinA new macrocyclic Schiff-base ligand, L, was synthesized by condensation reaction of 1,4-bis(2-formylphenyl) homopiperazine and 1,3-diaminopropane in acetonitrile. The Schiff-base ligand was characterized by using elemental analyses, IR, and mass spectroscopic techniques. Four new Ni(II), Cu(II), Co(II) and Zn(II) complexes of ligand, [NiLCl]ClO4, [CuLCl](ClO4), [CoLCl]ClO4 and [ZnLCl]ClO4 were prepared and characterized by elemental analyses and IR spectroscopy. X-ray crystal structure of [ZnLCl]ClO4 showed that the complex contains Zn(II) in a distorted square pyramidal geometry with a N4Cl core. In addition, structural parameters, vibration frequencies, frontier molecular orbitals (FMOs), UV bands and biological activity ranking of mentioned complexes are investigated as theoretically for all complexes. Computational studies of the relevant complexes are performed with the aid of density functional theory (DFT). (C) 2015 Elsevier B.V. All rights reserved.Öğe Synthesis, characterization, theoretical calculations, DNA binding and colorimetric anion sensing applications of 1-[(E)-[(6-methoxy-1,3-benzothiazol-2-yl)imino]methyl]naphthalen-2-ol(Elsevier Science Sa, 2015) Barare, Belygona; Yıldız, Mustafa; Alpaslan, Gökhan; Dilek, Nefise; Ünver, Fluseyin; Tadesse, Solomon; Aslan, KadirWe report the synthesis of a Schiff base 1-(E)-[(6-methoxy-1,3-benzothiazol-2-yl)imino]methyl] naphthalen-2-ol from the reaction of 2-hydroxy-1-naphtaldehyde with 2-amino-6-methoxybenzothiazole. The molecular structure of the title compound was experimentally determined using X-ray single-crystal data and was compared to the structure predicted by theoretical calculations using density functional theory (DFT). In addition, nonlinear optical (NLO) effects of the title compound was predicted using DFT. The colorimetric response of the title compound in DMSO to the addition of equivalent amount of anions (F-, CN-, H2PO4-, OH-, Br-, I-, SCN-, ClO4-, HSO4- N-3(-) and AcO-) was investigated. In this regard, while the addition of F-, CN-, H2PO4-, OH-, and AcO- anions into the solution containing the title compound resulted in a significant color change, the addition of Br-, I-, SCN-, ClO4-, HSO4- and N-3(-) anions resulted in no color change. The most discernable color change in the title compound was caused by CN-, which demonstrated that the title compound can be used to selectively detect CN-. The order of anion-binding power of the title compound was determined to be OH- > CN- > F- similar to AcO- > H2PO4-. The interactions between the receptor and anions were investigated using H-1 NMR titration method. Theoretical and UV-VIS spectroscopy studies of the interactions between the title compound and calf thymus DNA (CT-DNA) showed that the title compound interacts with CT-DNA via intercalative binding. (C) 2015 Elsevier B.V. All rights reserved.Öğe Synthesis, crystal structure, and spectroscopic studies of n-(4-bromobenzylidene)-n '-(2-pyridyl) hydrazine schiff base molecule(Taylor & Francis Ltd, 2012) Tunç, Tuncay; Tezcan, Habibe; Şahin, Ertan; Dilek, NefiseA new Schiff base complex N-(4-bromobenzylidene)-N'-(2-pyridyl) hydrazine, C12H10N3Br, has been synthesized and characterized by elemental analyses, mass, H-1 NMR, ultraviolet-visible (UV-VIS), and IR spectroscopy and single-crystal X-ray determination. The p-Br-benzene and pyridine rings are almost planar and the dihedral angle between the planes is 11.1(3)degrees. The crystal structure is stabilized by intermolecular N-H center dot center dot center dot N-Py hydrogen bonding interaction. X-ray diffraction analyses show that N-(4-bromobenzylidene)-N'-(2-pyridyl) hydrazine Schiff base molecule crystallizes in the monoclinic system, P2(1)/c space group, a = 5.611(5) angstrom, b = 19.566(5) angstrom, c = 10.715(5) angstrom, beta = 98.766(5)degrees, and V = 1162.60(12) angstrom(3).Öğe Synthesis, molecular structure, spectroscopic and theoretical studies on E-2-ethoxy-4-[(4-ethoxyphenylimino)methyl]phenol(Elsevier, 2015) Zeyrek, Celal Tuğrul; Alpaslan, Gökhan; Alyar, Hamit; Yıldız, Mustafa; Dilek, Nefise; Ünver, HüseyinSynthesis, crystallographic characterization, spectroscopic (FT-IR) and density functional modelling studies of a new Schiff base E-2-ethoxy-4-[(4-ethoxyphenylimino)methyl]phenol C17H19NO3 have been reported. The molecular structure obtained from X-ray single-crystal analysis of the investigated compound in the ground state has been compared using Hartree-Fock (HF) and density functional theory (DFT), B3LYP and B1B95 functional with the 6-311++G(d,p) basis set. In addition to the optimized geometrical structures, atomic charges, molecular electrostatic potential (MEP), natural bond orbital (NBO), nonlinear optical (NLO) effects and thermodynamic properties of the compound have been investigated by using DFT calculations. The electronic properties of the title compound in solvent media were also examined using the DFT calculations. The potential energy surface (PES) scans about important torsion angles are performed by using B3LYP/6-311++G (d,p) level of theoretical approximation for the compound. The experimental (FT-IR) and calculated vibrational frequencies (using DFT calculations) of the title compound have been compared. The predicted NLO properties of the compound which calculated by the B3LYP method with 6-31G(d), 6-31+G(d,p), 6-31++G(d,p), 6-311+G(d) and 6-311++G(d,p) basis sets are greater than ones urea. The standard thermodynamic functions were obtained for the title compound with the temperature ranging from 200 to 450 K. © 2015 Elsevier B.V. All rights reserved.Öğe Synthesis, structural characterization and DNA interaction of zinc complex from 2,6-diacetylpyridine dihydrazone and {4-[(2E)-2-(hydroxyimino)acetyl]phenoxy} acetic acid(Elsevier Science Sa, 2015) Güp, Ramazan; Gökçe, Cansu; Dilek, NefiseA new water soluble zinc complex has been prepared and structurally characterized. The Zn(II) complex was synthesized by the reaction of 2,6-diacetylpyridine dihydrazone (dph) with {4-[(2E)-2-(hydroxyimino) acetyl]phenoxy} acetic acid (H2L) in the presence of zinc(II) acetate. Single crystal X-ray diffraction study revealed that the zinc ion is situated in distorted trigonal-bipyramidal environment where the equatorial position is occupied by the nitrogen atom of pyridine ring and the oxygen atoms of acetate groups of two oxime ligands (H2L) whereas the axial positions of the zinc complex are occupied by the imine nitrogen atoms of dph ligand. Characterization of the complex with FTIR, H-1 and C-13 NMR, UV-vis and elemental analysis also confirmed the proposed structure. Interaction of the Zn(II) complex with calf-thymus DNA (CT-DNA) was investigated through UV-vis spectroscopy and viscosity measurements. The results suggest that the complex preferably bind to DNA through the groove binding mode. The zinc complex cleaves plasmid pBR 322 DNA in the presence and absence of an oxidative agent (H2O2), possibly through a hydrolytic pathway which is also supported by DNA cleave experiments in the presence of different radical scavengers. The nuclease activity of the zinc complex significantly depends on concentration of the complex and incubation time both in the presence and absence of H2O2. DNA cleave activity is inhibited in the presence of methyl green indicating that the zinc complex seems to bind the major groove of DNA. (C) 2015 Elsevier B.V. All rights reserved.
