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    (2,6-bis{1-[4-(dimethylamino)phenylimino]ethyl}pyridine)dichlorido(tri-phenylphosphine-?P)ruthenium(II): a zigzag chain of fused centrosymmetric R22(12) rings
    (Int Union Crystallography, 2007) Ozdemir, Namik; Dincer, Muharrem; Dayan, Osman; Cetinkaya, Bekir
    The title compound, [RuCl2(C25H29N5)(C18H15P)], a transfer hydrogenation catalyst, is supported by an N,N',N-tridentate pyridine-bridged ligand and triphenylphosphine. The Run centre is six-coordinated in a distorted octahedral arrangement, with the two Cl atoms located in the axial positions, and the pyridine (py) N atom, the two imino N atoms and the triphenylphosphine P atom located in the equatorial plane. The two equatorial Ru-N-imino distances (mean 2.093 angstrom) are substantially longer than the equatorial Ru-N-py bond [1.954 (4) angstrom]. It is observed that the N-imino-M-N-py bond angle for the five-membered chelate rings of 2,6-bis(imino)pyridine-based complexes is inversely related to the magnitude of the M-N-py bond. The title structure is stabilized by intra- and intermolecular C-H... Cl hydrogen bonds, as well as by intramolecular pi-pi stacking interactions between the aromatic rings belonging to the triphenylphosphine ligand and the dimethylaminophenyl fragment. The intermolecular 2 hydrogen bonds form an R-2(2)(12) ring and a zigzag chain of fused centrosymmetric rings running parallel to the [100] direction.
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    (2Z,6Z)-N2,N2?-bis(2,6-diisopropylphenyl)-N1,N1?-bis(2-methoxyethyl)pyridine-2,6-dicarboxamidine
    (Int Union Crystallography, 2008) Dincer, Muharrem; Ozdemir, Namik; Dayan, Osman; Cetinkaya, Bekir
    In the title compound, C37H53N5O2, the benzene rings make dihedral angles of 84.61 (8) and 67.10 (9)degrees with the pyridine ring. The crystal structure is stabilized by strong intramolecular interactions. The two (2-methoxyethyl) amine groups are disordered over two positions; the site occupancies are ca 0.6 and 0.4.
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    A light-detecting Ru(II)/Si heterojunction system involving a binuclear Ru (II) complex with pyridine-2,6-diimine (pydim) ligand
    (Springer, 2024) Koc, Muemin Mehmet; Dayan, Osman; Dere, Aysegul; Cetinkaya, Bekir; Coskun, Burhan; Yakuphanoglu, Fahrettin
    A meticulously detailed chemical procedure was employed to synthesize the Ru (II)-containing pyridine-2,6-diimine (pydim) organometallic complex. The resulting complex was then applied to Al-coated Si wafers using the spin-coating technique, leading to the production of Al/Ru(II) organometallic complex/n-Si/Al photodiodes. The light responsiveness of these photodiodes was demonstrated through the acquisition of I-V and I-t characteristics. Subsequently, essential parameters such as ideality factor, photosensitivity, barrier height, and photoresponse values were evaluated based on the obtained I-V and I-t plots. The calculations yielded ideality factors and barrier heights, resulting in average values of 6.41 and 0.552 eV, respectively. Furthermore, an in-depth analysis of the electrical properties of the diodes was conducted using G-V and C-V assessments, revealing a strong dependence on AC signal frequency. This investigation underscored that the observed frequency-related electrical behaviour is rooted in series resistance and interface states.
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    A neutral arene ruthenium(II) complex with a sulfonated N,O-chelating ligand: Synthesis, characterization, in vitro cytotoxicity and antibacterial activity
    (Pergamon-Elsevier Science Ltd, 2020) Selvi, Gizem; Ozdemir, Fethi Ahmet; Aykutoglu, Gurkan; Ozdemir, Namik; Serbetci, Zafer; Cetinkaya, Bekir; Dayan, Osman
    In this work, a new N,O-type ligand (L1H) containing a sulfonate ester group and its heteroleptic Ru(II) complex (C1) have been prepared and structurally characterized by various techniques, such as UV-vis, ESI-MS, NMR and IR. The spectroscopic results (IR, UV-vis and NMR) were compared with the results of density functional theory (DFT) calculations. The solid-state structures of L1H and C1 were crystallographically verified. Moreover, the in vitro cytotoxicity and antibacterial properties of 1, L1H and Cl have been screened. All the compounds exhibited good cytotoxicity towards human neuroblastoma cancer cells and antibacterial effects towards 16 bacterial strains, both gram positive and negative. The results revealed that the Ru(II) complex exhibits higher biological activities than the starting materials 1 and L1H. (C) 2019 Elsevier Ltd. All rights reserved.
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    (Acetonitrile){2,6-bis[1-(2,4,6-trimethylphenylimino)ethyl]pyridine} dichloridoruthenium(II) dichloromethane solvate
    (Int Union Crystallography, 2007) Ozdemir, Namik; Dincer, Muharrem; Dayan, Osman; Cetinkaya, Bekir
    In the title compound, [RuCl2(C2H3N)(C27H31N3)] center dot CH2Cl2, the Ru-II ion is six-coordinated in a distorted octahedral arrangement, with the two Cl atoms located in the apical positions, and the pyridine (py) N atom, the two imino N atoms and the acetonitrile N atom located in the basal plane. The two equatorial Ru - N-imino distances are almost equal ( mean 2.087 angstrom) and are substantially longer than the equatorial Ru - N-py bond [1.921 ( 4) angstrom]. It is observed that the N-imino-M-N-py angle for the five-membered chelate rings of pyridine-2,6-diimine complexes is inversely related to the magnitude of the M-N-py bond. The title structure is stabilized by intra- and intermolecular C-H center dot center dot center dot Cl hydrogen bonds, as well as by van der Waals interactions.
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    Bis{2,6-bis[1-(4-fluorophenylimino)ethyl]pyridine}-1?3N,N?,N;3?3N,N?,N-di-?-chlorido-1:2?2Cl:Cl;-2:3?2Cl:Cl-trichlorido-1?Cl,2?Cl,3?Cl-2-copper(I)-1,3-dicopper(II)
    (Int Union Crystallography, 2008) Ozdemir, Namik; Dincer, Muharrem; Dayan, Osman; Cetinkaya, Bekir
    The title complex, [Cu3Cl5(C21H17N3F2)(2)], is the first reported copper trimer including both Cu-I and Cu-II ions. The two Cu-II ions are five-coordinate in a significantly distorted square-pyramidal arrangement, with the bridging Cl atom located in the apical position, and the pyridine (py) N atom, the two imine N atoms and the other Cl atom located in the basal plane. The Cu-I ion is in a trigonal planar configuration surrounded by three Cl atoms. The structure is stabilized by intra- and intermolecular C-H center dot center dot center dot Cl and C-H center dot center dot center dot pi(py) hydrogen bonds.
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    Concomitant polymorphism of a pyridine-2,6-dicarboxamide derivative in a single space group: Experimental and molecular modeling study
    (Pergamon-Elsevier Science Ltd, 2012) Ozdemir, Namik; Dayan, Osman; Cetinkaya, Bekir; Akgul, Cahit
    The title compound, N-2,N-6-bis{2-[(Z)-2-hydroxybenzylideneamino]phenyl}pyridine-2,6-dicarboxamide (3), has been synthesized by the reaction of 2-{(2-aminophenylimino)methyl}phenol (1) with pyridine2,6-dicarbonyl dichloride (2), and characterized by elemental analysis. FT-IR and NMR spectroscopies and thermal analysis. Compounds 1 and 3 were evaluated for their antibacterial activities against Grampositive and Gram-negative bacteria. The catalytic activity of 3 was also studied, and as a result, the in situ prepared three component system Ru(II)/3/KOH is shown to be an efficient catalyst for the transfer hydrogenation reaction of various ketones under mild conditions. Compound 3 has been crystallized in two polymorphic forms under the same conditions, and their crystal structures have been determined using single crystal X-ray diffraction technique. The molecular geometry, vibrational frequencies and gauge-independent atomic orbital (CIAO) H-1 and C-13 NMR chemical shift values of 3 in the ground state have been calculated using the density functional theory (DFT/B3LYP) method with the 6-31G(d) basis set, and compared with the experimental data. The results are in good agreement with experimental data. The effect of different solvents on the geometry, vibrational frequencies, total energies and dipole moments was also studied using the same method by applying the Onsager Model. There are subtle differences in the conformations and packing of the two polymorphs as a consequence of intermolecular hydrogen bonding interactions. Therefore, DFT calculations for the hydrogen bond interactions in the polymorphs were carried out using same basis set. The changes of thermodynamic properties from the monomers to 3 with the temperature ranging from 200 K to 400 K have been obtained using the statistical thermodynamic method. (C) 2011 Elsevier B.V. All rights reserved.
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    N-(2,6-diisopropylphenyl)-6-[(2,6-diisopropylphenyl)(methacryloyl)aminocarbonyl]pyridine-2-carboximidoyl chloride
    (Int Union Crystallography, 2007) Aydin, Aslihan; Dincer, Muharrem; Dayan, Osman; Cetinkaya, Bekir
    In the title compound, C35H42ClN3O2, molecules are linked to one another by intermolecular C-H center dot center dot center dot O interactions, forming a C( 12) chain running parallel to the [ 010] direction. The molecule has a nonplanar conformation. The benzene rings make dihedral angles of 72.72 ( 6) and 62.72 ( 6)degrees with the pyridine ring.
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    Palladium(II) Complexes Containing 2,6-Bis(Imino)Pyridines: Synthesis, Characterization, Thermal Study, and Catalytic Activity in Suzuki Reactions
    (Taylor & Francis Inc, 2010) Dayan, Osman; Doğan, Fatih; Kaya, İsmet; Cetinkaya, Bekir
    A series of palladium complexes: [(Pydim)PdCl](PdCl3) (Pydim (1): pyridine-2,6-diimine) have been synthesized from palladium dichloride and the corresponding pydim. The Pd (II) complexes have been used as catalyst in the Suzuki reaction of aryl halides. Moreover, thermal behaviors of palladium complexes have been studied in nitrogen atmosphere using TG/DTG and DTA techniques. The values of activation energy Ea, and reaction order n, the entropy change S*, enthalpy change H#, and Gibbs free energy change G# of the thermal decomposition were calculated by means of several methods based on the single heating rate.
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    Preparation and crystal structure of binuclear chloro{6-[[chloro(triphenylphosphine)platinum](mesitylimino)methyl]pyridin-2-yl}bis(triphenylphosphine)platinum(II)
    (Pergamon-Elsevier Science Ltd, 2008) Gunay, M. Emin; Dayan, Osman; Gokce, Aytac Gurhan; Aygun, Muhittin; Cetinkaya, Bekir; Buyukgungor, Orhan
    Treatment of N,N'-bis(mesityl)pyridine-2,6-carboxyimidoyldichloride, 1, in toluene solution with [Pt(PPh3)(4)] at 100 degrees C afforded a novel platinacyclic compound, 3, in 63% yield, instead of the expected compound 2. The molecular and crystal structures of the title compound, 3, have been determined by the single crystal X-ray diffraction technique. The coordination geometries around the Pt atoms are distorted square-planar. In the crystal structure, the molecules are linked by a pair of C-H center dot center dot center dot N hydrogen bonds into a centrosymmetric dinner with an R-2(2) (16) ring, centred at (1/2,1/2,1/2). (C) 2008 Elsevier Ltd. All rights reserved.
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    Ruthenium(II) complexes bearing pyridine-based tridentate and bidentate ligands: catalytic activity for transfer hydrogenation of aryl ketones
    (Wiley, 2012) Dayan, Osman; Dayan, Serkan; Kani, Ibrahim; Cetinkaya, Bekir
    Ru(II) complexes of the general formula [RuCl2('NNN??')(L)] (1: 'N?=?Nb, L?=?MeOH; 2: 'N?=?Nb, L?=?CH3CN; 3: 'N?=?Nd, L?=?CH3CN; 4: 'N?=?Np, L?=?CH3CN), [Ru(p-cymene)(NN?ab)Cl]Cl (5a: N?Na?=?2,2'-bipyridine; 5b: N?Nb?=?4,4'-dimethyl2,2'-bipyridine), [Ru('NNN??')(NN?ab)Cl]Cl (6a: 'N?=?Nb, NN?a?=?2,2'-bipyridine; 6b: 'N?=?Nb, NN?b?=?4,4'-dimethyl-2,2'-bipyridine; 7a: 'N?=?Nd, NN?a?=?2,2'-bipyridine; 7b: 'N?=?Nd, NN?b?=?4,4'-dimethyl-2,2'-bipyridine; 8a: 'N?=?Np, NN?a?=?2,2'-bipyridine; 8b: 'N?=?Np, NN?b?=?4,4'-dimethyl-2,2'-bipyridine) and [Ru('NNN??')(NN?a)Cl]BF4 (9a: 'N?=?Nb; NN?a?=?2,2'-bipyridine) were synthesized from the corresponding [RuCl2(p-cymene)]2 dimer, 'NNN??' and NN?ab ligands. The compounds were characterized by elemental analysis, IR and NMR. Complex 9a was studied by X-ray diffraction, confirming its cationic-mononuclear [RuCl(bNNN??b)(NN?a)]+ nature. The synthesized Ru(II) complexes (18) were employed as catalysts for the transfer hydrogenation of ketones to secondary alcohols in the presence of KOH using 2-propanol as a hydrogen source at 82 degrees C. The rates of the transfer hydrogenation reactions strongly depended on the type of NNN?? and ancillary ligands. Copyright (C) 2012 John Wiley & Sons, Ltd.
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    Synthesis and catalytic activity of ruthenium(II) complexes containing pyridine-based tridentate triamines ('NNN') and pyridine carboxylate ligands (NO)
    (Elsevier Science Sa, 2012) Dayan, Osman; Ozdemir, Namik; Serbetci, Zafer; Dincer, Muharrem; Cetinkaya, Bekir; Buyukgungor, Orhan
    The reaction of [(p-cymene)RuCl2](2) with K[NOa-b] (NO- = 2-picolinate, a or 2-quinaldinate, b) gave neutral [(p-cymene)RuCl(NOa-b)] (1a-b), complexes which were treated with pyridine-based meridional triamine ligands ('NNN') to create complexes of the type [RuCl(NOa-b)('NNN')] (2a: 'N = N-d, NOa(-) = 2-picolinato; 2b: 'N = N-d, NOb- = 2-quinaldinato; 3a: 'N = N-b, NOa- = 2-picolinato; 3b: 'N = N-b, NOb- = 2-quinaldinato; 4a: 'N = N-p, NOa- = 2-picolinato; 4b: 'N = N-p, NOb- = 2-quinaldinato). The new compounds were characterized by elemental analysis, IR and NMR spectroscopy and, 1b was studied by single crystal X-ray diffraction. The complexes 1-4 have been employed as catalysts for the transfer hydrogenation (TH) of acetophenone derivatives to secondary alcohols in the presence of KOH using 2-propanol as a hydrogen source at 82 degrees C. The highest catalytic activity was obtained with 3a. (C) 2012 Elsevier B. V. All rights reserved.
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    Synthesis and characterization of 2,2?-(pyridine-2,6-diyl)bis (1H-benzo[d]imidazol-3-ium) 2,4,6-trimethylbenzenesulfonate chloride by experimental and theoretical methods
    (Pergamon-Elsevier Science Ltd, 2014) Ozdemir, Namik; Dayan, Osman; Yavasoglu, Melek Tercan; Cetinkaya, Bekir
    The title molecular salt (2), 2,2 '-(pyridine-2,6-diyl)bis (1H-benzo[d]imidazol-3-ium) 2,4,6-trimethylbenzenesulfonate chloride (C19H15N52+center dot C9H11O3S-.Cl-), was synthesized unexpectedly from the reaction of 2,6-bis(benzimidazol-2-yl)pyridine (1) with 2-mesitylenesulfonyl chloride. Spectroscopic techniques NMR and UV-vis.) were used to characterize compounds 1 and 2. Solid-state structure of compound 2 was identified by X-ray crystallography. Theoretical characterization of the spectroscopic properties of compounds 1 and 2 was achieved using the density functional theory (DFT) method with the 6-311G(d,p) basis set, and the results were checked against the experimental data. Electronic absorption spectra of the compounds have also been obtained. (C) 2014 Elsevier B.V. All rights reserved.
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    Synthesis and photovoltaic properties of new Ru(II) complexes for dye-sensitized solar cells
    (Springer, 2018) Dayan, Osman; Ozdemir, Namik; Yakuphanoglu, Fahrettin; Serbetci, Zafer; Bilici, Ali; Cetinkaya, Bekir; Tercan, Melek
    Two groups Ru(II) complexes, (1A-C and 2A) (A-C = 2,6-bis(2-benzimidazolyl)pyridines, bbpy, with various substituents at 2-, 5-, and 6-positions) have been prepared and applied for dye-sensitized solar cells (DSSC). The compounds were characterized by various techniques. The optical and electrical properties of sensitizers were investigated with UV-Vis absorption spectroscopy and cyclic voltammetry. High power conversion efficiencies up to 5.16%, have been achieved with 2Ae. Current-voltage characteristics of DSSCs clearly affected by the changing of the ligands at sensitizers. Additionally, computational studies show that locations of frontier molecular orbitals are significantly important for power-conversion efficiencies in DSSCs.
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    Synthesis of Ruthenium(II) Complexes Containing Tridentate Triamine (?(NNN)over-cap?) and Bidentate Diamine Ligands ((NN)over-cap?): as Catalysts for Transfer Hydrogenation of Ketones
    (Amer Chemical Soc, 2011) Gunnaz, Salih; Ozdemir, Namik; Dayan, Serkan; Dayan, Osman; Cetinkaya, Bekir
    A series of neutral and cationic Ru(II) complexes (1-10), bearing pyridine-based tridentate ('(NNN) over cap'), pyridine-based bidentate ((NN) over cap'), and mixed '(NNN) over cap' + (NN) over cap' ligands, were synthesized by starting from [RuCl2(DMSO)(4)] and [RuCl2(p-cymene)](2) precursors. Solid-state structures of mixed-ligand complexes 9 and 10 were determined by single-crystal X-ray diffraction. Both complexes are unusual in that (NN) over cap' ligands were spontaneously oxidized in air under base-free conditions to give imine-amine bidentate ligands upon replacement of p-cymene by meridional '(NNN) over cap'. The complexes 1-10 were screened for transfer hydrogenation (TH) of aryl ketones with, 2-propanol. The highest catalytic activity was obtained with the :complexes containing tridentate '(NNN) over cap' and 7, which contain nonsulfonated 2-(aminomethyl)pyridine. However, for complexes 6(a-c), containing p-cymene (a facial tridentate ligand), a slower reaction rate was observed.
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    Synthesis, DFT computations and antimicrobial activity of a Schiff base derived from 2-hydroxynaphthaldehyde: Remarkable solvent effect
    (Elsevier, 2020) Tercan, Melek; Ozdemir, Namik; Ozdemir, Fethi Ahmet; Serbetci, Zafer; Erdener, Digdem; Cetinkaya, Bekir; Dayan, Osman
    A new Schiff base bearing sulfonamide group was synthesized and characterized by spectroscopic techniques. Its spectroscopic properties were investigated through density functional theory (DFT/B3LYP) method with the 6-311++G(d,p) basis set theoretically and the zwitterion reversible arrow enol tautomerization was studied using IEF-PCM approximation. The thermodynamic (entropy, enthalpy and Gibbs free energy changes) and energetic quantities of the zwitterion reversible arrow enol tautomerization indicate that the migration of single proton between zwitterion reversible arrow enol tautomer's is unfavored for both directions in all phases. During the change from the water phase to the gas phase, the tautomeric energy barrier increases for the proton transfer reaction from the zwitterion form to the enol form, while the barrier decreases from the enol form to the zwitterion form. On the other hand, experimental studies (UV-vis. and NMR spectroscopies) release that there are two tautomeric species which are the zwitterion form in polar and the enol form in apolar solvents for the soluted compound. Furthermore, the antibacterial effect of the compound was investigated in two different solvents (DMSO and THF) to demonstrate the effect of dominant tautomeric species. The results indicate that the solution in which the enol form is dominant than the zwitterionic form has more antimicrobial efficiency for all bacterial species. (C) 2020 Elsevier B.V. All rights reserved.
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    Synthesis, spectroscopic characterization, X-ray structure and DFT studies on 2,6-bis(1-benzyl-1H-benzo[d]imidazol-2-yl)pyridine
    (Pergamon-Elsevier Science Ltd, 2013) Inkaya, Ersin; Gunnaz, Salih; Ozdemir, Namik; Dayan, Osman; Dincer, Muharrem; Cetinkaya, Bekir
    The title molecule, 2,6-bis(1-benzyl-1H-benzo[d]imidazol-2-yl)pyridine (C33H25N5), was synthesized and characterized by elemental analysis, FT-IR spectroscopy, one- and two-dimensional NMR spectroscopies, and single-crystal X-ray diffraction. In addition, the molecular geometry, vibrational frequencies and gauge-independent atomic orbital (GIAO) H-1 and C-13 NMR chemical shift values of the title compound in the ground state have been calculated using the density functional theory at the B3LYP/6-311G(d,p) level, and compared with the experimental data. The complete assignments of all vibrational modes were performed by potential energy distributions using VEDA 4 program. The geometrical parameters of the optimized structure are in good agreement with the X-ray crystallographic data, and the theoretical vibrational frequencies and GIAO H-1 and C-13 NMR chemical shifts show good agreement with experimental values. Besides, molecular electrostatic potential (MEP) distribution, frontier molecular orbitals (FMO) and non-linear optical properties of the title compound were investigated by theoretical calculations at the B3LYP/6-311G(d,p) level. The linear polarizabilities and first hyper polarizabilities of the molecule indicate that the compound is a good candidate of nonlinear optical materials. The thermodynamic properties of the compound at different temperatures were calculated, revealing the correlations between standard heat capacity, standard entropy, standard enthalpy changes and temperatures. (c) 2012 Elsevier B.V. All rights reserved.