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Öğe A combined experimental (XRD, FT-IR, UV-VIS and NMR) and theoretical (NBO, NLO, local & global chemical activity) studies of methyl 2-((3R,4R)-3-(naphthalen-1-yl)-4-(phenylsulfonyl) isoxazolidin-2-yl) acetate(Elsevier, 2020) Gultekin, Zeynep; Demircioglu, Zeynep; Frey, Wolfgang; Buyukgungor, OrhanMethyl 2-((3R,4R)-3-(naphthalen-1-yl)-4-(phenylsulfonyl) isoxazolidin-2-yl) acetate (3e) was synthesized and characterized by XRD, FT-IR, UV-Vis and NMR techniques. All theoretical computations were calculated by using density functional theory (DFT) B3LYP method with the help of 6-311G(d,p) basis set. Theoretical calculations help to obtain detailed information about local & global chemical activities, molecular and chemical properties which are reveal the electrophilic and nucleophilic nature. Accordingly, global (FMOs, hardness & softness parameters) and local (MEP, FF, net charges) chemical activity descriptors were examined. To determine the non-linear optical behaviours of title compound; the total dipole moment, mean polarizability and first-order hyperpolarizability values have been examined. (C) 2019 Published by Elsevier B.V.Öğe A disparate 3-D silver(I) coordination polymer of pyridine-3,5-dicarboxylate and pyrimidine with strong intermetallic interactions: X-ray crystallography, photoluminescence and antimicrobial activity(Taylor & Francis Ltd, 2015) Alisir, Sevim Hamamci; Demir, Serkan; Sariboga, Bahtiyar; Buyukgungor, OrhanA polymeric silver(I) complex, [Ag-4(-pydc)(2)(-pm)(2)](n) (1) (pydc=pyridine-3,5-dicarboxylate and pm=pyrimidine), has been synthesized and characterized by elemental analysis, IR spectroscopy, thermal analysis, and single-crystal X-ray diffraction. X-ray crystallographic data of 1 revealed that pydc exhibits two different coordinaton modes that play a key role in the construction of the 3-D crystal network including Ag-carboxylate clusters in which close Ag-Ag distances exist. The magnitudes of close Ag-Ag interactions in second-order energy (E-2) have been revealed by natural bond orbital analysis performed with single point energy calculation using the experimental geometry of 1. Furthermore, the luminescent properties of 1 show strong fluorescence with two emission maxima in the visible region. Also, 1 has antifungal activity on Candida albicans (MIC value, 4gmL(-1)) and good antibacterial activity on micro-organisms (MIC value, 64-256gmL(-1)).Öğe A theoretical insight for solvent effect on myoglobin assay of W(CO)4L2 type novel complexes with DFT/TDDFT(Elsevier Science Bv, 2016) Ustun, Elvan; Demir, Serpil; Coskun, Feyzullah; Kaloglu, Murat; Sahin, Onur; Buyukgungor, Orhan; Ozdemir, IsmailNovel tetracarbonyl complexes of type W(CO)(4)L-2 (L: 4-chlorobenzylimidazoline; 4-methylbenzylimidazoline; 3,5-dimethylbenzylimidazoline; 2,4,6-trimethylbenzylimidazoline; 2,3,5,6-tetramethylbenzylimidazoline) were synthesized. Then newly synthesized novel compounds were characterized by IR, H-1 NMR, C-13 NMR and LC-MS. The characterizations of two of the complexes have also been confirmed with single crystal X-Ray diffraction and OFT optimization results of these complexes have been compared with single crystal results. We have investigated the solvent effect on the structure and metal-to-ligand charge transfer (MLCT) transitions with OFT/TDDFT calculations with ORCA package program with BP86 functional. (C) 2016 Elsevier B.V. All rights reserved.Öğe Analysis of tautomeric equilibrium in (E)-4,6-dibromo-2-[(4-fluorophenylimino)methyl]-3-methoxyphenol compound(Pergamon-Elsevier Science Ltd, 2015) Kastas, Cigdem Albayrak; Kastas, Gokhan; Gur, Mahmut; Muglu, Halit; Buyukgungor, OrhanIn this study, the tautomeric equilibrium between the phenol-imine and keto-amine structural forms of (E)-4,6-dibromo-2-[(4-fluorophenylimino)methyl]-3-methoxyphenol compound has been investigated with experimental (XRD, UV-vis and NMR) and theoretical (DFT and TD-DFT) methods. The results clearly show that structural preference of the compound is definitely depended on its state. Namely, the compound exists in phenol-imine form in the solid state while one or both of these forms can be seen in solvent media. For example, the compound prefers phenol-imine form in benzene while both forms exist in EtOH and DMSO solvents. Coexistence of two forms has been quantified with NMR studies, giving a ratio of 11:9 for phenol and keto structures of the compound in acetone-d(6) solvent. (C) 2015 Elsevier B.V. All rights reserved.Öğe Boric acid complexes with thiamine (vitamin B1) and pyridoxine (vitamin B6)(Elsevier Science Sa, 2014) Kose, Dursun Ali; Zumreoglu-Karan, Birgul; Sahin, Onur; Buyukgungor, OrhanComplexation of boric acid with vitamins B1 (thiamine) and B6 (pyridoxine) was investigated. The products were isolated from aqueous solutions and characterized by elemental analysis, FT-IR, C-13 MAS NMR and thermal methods. The results of chemical and spectral analyses suggested that the reaction between thiaminechloride hydrochloride and H3BO3 in water yielded a salt-like productwith no direct bonding of the thiamine cation to boron while mono- and bis-chelate complexes were obtained with pyridoxine. The bis-chelate pyridoxine complex containing two equivalent pyridoxine ligands was obtained in crystal form. X-ray crystallography verified that complexation with boric acid occurs through the deprotonated phenolic and deprotonated adjacent alcoholic oxygen atoms forming six membered chelate rings. The negative charge on tetrahedral boron is balanced by the sodium ion. The crystal structure contains discernible tunnels parallel to the [010] direction constructed by hydrogen bonded complex molecules. (c) 2014 Elsevier B.V. All rights reserved.Öğe Crystal Structure and Quantum Mechanical Calculations of (E)-4-methoxy-2-[(o-tolylimino)methyl] phenol.(Int Union Crystallography, 2009) Ozek, Arzu; Buyukgungor, Orhan; Albayrak, Cigdem; Odabasoglu, Mustafa[No abstract available]Öğe Crystal Structure of (E)-3-[(4-Ethylphenylimino)methyl]benzene-1,2-diol and (E)-3-[( 4-Butylphenyl imino)methyl]benzene-1,2-diol.(Int Union Crystallography, 2009) Kelesoglu, Zeynep; Kosar, Basak; Albayrak, Cigdem; Odabasoglu, Mustafa; Buyukgungor, Orhan[No abstract available]Öğe CRYSTAL STRUCTURE, SPECTRAL CHARACTERIZATION, MOLECULAR MODELING STUDIES AND STRUCTURAL EFFECTS OF THE PROTON TRANSFER PROCESS FOR (E)-5-METHOXY-2-[(3,4-DIMETHYLPHENYLIMINO)METHYL]PHENOL(Soc Chemists Technologists Madeconia, 2017) Kirca, Basak Kosar; Tari, Gonca Ozdemir; Kastas, Cigdem Albayrak; Odabasoglu, Mustafa; Buyukgungor, OrhanThe main purpose of this study is to characterize a new organic material, (E)-5-methoxy-2-[(3,4-dimethylphenylimino) methyl] phenol, which was synthesized and grown as a single crystal. The molecular structure and spectroscopic properties of the ortho-hydroxy Schiff base compound were determined by X-ray diffraction analysis, Fourier-transform infrared (FT-IR), ultraviolet-visible (UV-Vis) and nuclear magnetic resonance (NMR) spectroscopy techniques, experimentally and computationally with density functional theory (DFT) calculations. X-ray and UV-Vis studies show that the compound exists in an OH tautomeric form in the solid and solvent media. The gas phase geometry optimizations of two possible forms of the title compound, resulting from the prototropic tautomerism, were obtained using DFT calculations at the B3LYP/6-311G+(d,p) level of theory. A relaxed potential energy surface (PES) scan was performed based on the optimized geometry of the OH tautomeric form by varying the redundant internal coordinate, the O-H bond distance. According to the PES scan process, the molecular geometry is strongly affected by the intramolecular proton transfer. The calculated first hyperpolarizability indicates that the compound could be a good material for non-linear optical applications.Öğe Crystal structure, spectroscopic investigations and quantum chemical calculation studies of (3aR,6S,7aR)-7a-bromo-6-methyl-2-[(4-methylphenyl)sulfonyl]-1,2,3,6,7,7a-hexahydro-3a,6-epoxyisoindole: A combined experimental and theoretical studies(Elsevier, 2016) Alasalvar, Can; Demircan, Aydin; Kosar, Basak; Pekacar, Ali Ihsan; Buyukgungor, OrhanThe crystal structure and spectroscopic properties of (3aR,65,7aR)-7a-bromo-6-methyl-2-[(4-methylphenyl)sulfonyl]-1,2,3,6,7,7a-hexahydro-3a,6-epoxyisoindole were determined by X-ray diffraction, IR and (CNMR)-C-13 and H-1 NMR spectroscopytechniques. We investigate molecular and crystal structure of the new sulfonamide, which was derived from an environmental friendly cyclization reaction in water. This work allow to the development of a stereo-selective tandem allylamine isomerization/Diels Alder cyclo-addition sequence led to rapid assembly of complex nitrogen containing heterocycles. The molecular geometry from X-ray determination, vibrational frequencies and NMR shifts values of the title compound in the ground state have been calculated by using CAM-B3LYP and B3LYP methods with 6-311++G(d,p) basis sets. The calculated results show that the optimized geometry can well regenerate the crystal structure and theoretical vibrational frequencies and chemical shift data are in good agreement with experimental data. Besides, it is examined nonlinear optic properties, molecular electrostatic potential map and HOMO-LUMO orbitals of the molecule. (C) 2016 Elsevier B.V. All rights reserved.Öğe Design and construction of six coordination polymers with imidazole-4,5-dicarboxylate ligand(Elsevier Science Sa, 2015) Erer, Hakan; Yesilel, Okan Zafer; Sahin, Onur; Buyukgungor, OrhanSix new metal-organic frameworks based on a rigid multifunctional ligand imidazole 4,5-dicarboxylic acid (H(3)idc), namely, [Zn-3(mu(3)-idc)(mu(5)-idc)](n) (1), {[Zn-3(mu(3)-idc)(2)(H2O)(dpeten)](n)center dot 2H(2)O}(n) (2), [Zn(mu-Hidc)-( mu-obix)(0.5)](n) (3), [Zn-4(mu-Hidc)(4)(mu-mbix)(2)](n) (4), {[Cd-5(mu(5)-idc)(2)(mu(4)-Hidc)(2)(H2O)(2)]center dot 2H(2)O}(n) (5) and [Cd-2(mu(3)-Hidc)(2)(mu-obix)](n) (6) (H(3)idc = imidazole-4,5-dicarboxylic acid, obix = 1,2-bis(imidazol-1-yl-methyl)-benzene, mbix = 1,3-bis(imidazol-1-yl-methyl)-benzene and dpeten = 1,2-di(pyridin-4-yl)ethene), have been constructed under hydro(solvo)thermal conditions and structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction, powder X-ray diffraction (PXRD) and thermal analyses (TG, DTA, DSC) techniques. In these compounds, the ligand, H(3)idc, exhibits different coordination modes, constructing various architectures by bridging a variety of metal ions or polynuclear clusters. All of these coordination polymers exhibited intense fluorescent emissions in the solid state at room temperature. Furthermore, topological properties were studied. (C) 2015 Elsevier B.V. All rights reserved.Öğe Diaquabis(5-methoxyindole-2-carboxylato)bis(3-picoline)nickel(II) Complex: Synthesis, Characterization, XRD, TGA, DFT and HSA(Taylor & Francis Ltd, 2018) Cebe, Demet; Heren, Zerrin; Demircioglu, Zeynep; Buyukgungor, OrhanA new complex of diaquabis(5-methoxyindole-2-carboxylato)bis(3-picoline)nickel(II) (Ni(5-MeOI2CA)(2)(3-pic)(2)(H2O)(2)), was synthesized for the first time and characterized by elemental analysis, FT-IR and electronic spectroscopy (UV-Vis) and single-crystal X-ray diffraction (XRD) techniques. The thermal degradation of the Ni(II) complex was investigated using thermogravimetric and differential thermal analyses techniques in oxygen atmosphere. The molecular structure of the complex was determined by single crystal X-ray diffraction technique. Hirshfeld surface analysis (HSA) investigated the packing modes and intermolecular interactions in molecular crystals, as they provide a visual picture of intermolecular interactions. In addition, all computational studies at B3LYP/6-311++G(d,p) were carried out for theoretical characterization of Ni(II) complex. The optimized geometry results, which were well represented the X-ray data, were shown that the chosen of DFT/B3LYP/6-311++G(d,p) was a successful choice for title compound. After a successful optimization, FMOs, chemical activity, non-linear optical properties (NLO), molecular electrostatic potential (MEP), Mulliken population (MPA), natural population analyses (NPA), Fukui function analysis (FFA) and natural bond orbital analysis (NBO), which could not obtained by experimental ways, were calculated and investigated. The computed of net charges and chemical activity studies which helped to identifying the electrophilic/nucleophilic nature.Öğe Dinuclear zinc(II) complex with tris(2-aminoethyl) amine ligand: synthesis, structure and properties(Walter De Gruyter Gmbh, 2015) Kurkcuoglu, Gunes Suheyla; Yesilel, Okan Zafer; Sahin, Onur; Sayin, Elvan; Buyukgungor, OrhanThe dinuclear complex tris(2-aminoethyl) aminezinc(II)-mu-cyanothreecyanozincate(II) hemihydrate, [Zn(tren) Zn(mu-CN)(CN)(3)]center dot 0.5H(2)O (1) (tren = tris(2-aminoethyl)amine), has been synthesized and characterized by spectral (FT-IR and Raman), elemental, thermal analysis (TG, DTG and DTA) as well as single crystal X-ray diffraction techniques. The asymmetric unit is composed of two Zn(II) ions, one tren ligand, four cyanide ligands and a half crystal water molecule which is situated at the special position. Zn1 ion exhibits tetrahedral coordination geometry with four carbon atoms of four cyanide ligands. Zn2 ion is five-coordinated by five nitrogen atoms from one tren and one cyanide ligands in a trigonal bipyramid coordination geometry. The cyanide nitrogen is in the axial position. Adjacent dinuclear units are connected by hydrogen bonding interactions to form three dimensional network. The decomposition reaction takes place in the temperature range 30-700 degrees C in the static air atmosphere.Öğe (E)-1-[4-(2-hydroxy-5-methoxybenzylideneamino)phenyl]ethanone and (E)-1-[4-(2-hydroxy-4-methoxybenzylideneamino)phenyl]ethanone: X-ray and DFT-calculated structures(Elsevier, 2011) Sahin, Onur; Buyukgungor, Orhan; Albayrak, Cigdem; Odabasoglu, MustafaThe isomeric structures of (E)-1-[4-(2-hydroxy-5-methoxybenzylideneamino)phenyl] ethanone (I) and (E)-1-[4-(2-hydroxy-4-methoxybenzylideneamino)phenyl]ethanone (II), both C16H15NO3, have been determined using X-ray diffraction techniques and characterized by IR, and their molecular structures have also been optimized at the B3LYP/6-31G(d,p) level using density functional theory (DFT). The energetic behaviors of the title compounds in solvent media have been examined using B3LYP method with the 6-31G(d,p) basis set by applying the polarizable continuum model (PCM). The total energies of the title compounds decrease with the increasing polarity of the solvent. In addition, DFT calculations of the title compounds' molecular electrostatic potentials (MEP) were performed at the B3LYP/6-31G(d,p) level of theory. X-ray study shows that the title compounds both have strong intramolecular O-H center dot center dot center dot N hydrogen bonds. The molecules of! are linked into a one-dimensional framework structure by C-H center dot center dot center dot pi interactions, while in II, intermolecular pi center dot center dot center dot pi interactions result in the formation of infinite chains running along the [010].Öğe (E)-2-[(4-Chlorophenyl)iminomethyl]-5-methoxyphenol and (E)-2-[(2-chlorophenyl)iminomethyl]-5-methoxyphenol: X-ray and DFT-calculated structures(Int Union Crystallography, 2009) Kosar, Basak; Albayrak, Cigdem; Odabasoglu, Mustafa; Buyukgungor, OrhanThe crystal structures of the title 4-chlorophenyl, (I), and 2-chlorophenyl, (II), compounds, both C14H12ClNO2, have been determined using X-ray diffraction techniques and the molecular structures have also been optimized at the B3LYP/6-31 G(d, p) level using density functional theory (DFT). The X-ray study shows that the title compounds both have strong intramolecular O-H center dot center dot center dot N hydrogen bonds and that the crystal networks are primarily determined by weak C-H center dot center dot center dot pi and van der Waals interactions. The strong intramolecular O-H center dot center dot center dot N hydrogen bond is evidence of the preference for the phenol-imine tautomeric form in the solid state. The IR spectra of the compounds were recorded experimentally and also calculated for comparison. The results from both the experiment and theoretical calculations are compared in this study.Öğe Existence of a resonance hybrid structure as a result of proton tautomerism in (±)-(E)-4-Bromo-2-[(2,3-dihydroxypropylimino)methyl]phenol racemate(Pergamon-Elsevier Science Ltd, 2014) Albayrak, Cigdem; Kastas, Gokhan; Odabasoglu, Mustafa; Buyukgungor, Orhano-Hydroxy Schiff bases have two tautomers known as phenol-imine and keto-amine forms. In the present work, the tautomerism in (E)-4-Bromo-2-[(2,3-dihydroxypropylimino)methyl]phenol compound has been investigated by experimental (XRD, FT-IR and UV-vis) and computational (DFT and TD-DFT) methods. The X-ray diffraction (XRD) study reveals that the title compound favors a resonance hybrid structure of phenol-imine and keto-amine forms in the solid state rather than having these forms separately or jointly. Experimental UV-vis study of proton transfer process in solvent media (Benzene, DMSO and EtOH) shows the preference of phenol-imine form in benzene while both phenol-imine and keto-amine characteristics are present in EtOH and DMSO. (C) 2013 Elsevier B.V. All rights reserved.Öğe Experimental (X-ray, FT-IR and UV-vis spectra) and theoretical methods (DFT study) of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol(Pergamon-Elsevier Science Ltd, 2014) Demircioglu, Zeynep; Albayrak, Cigdem; Buyukgungor, OrhanA suitable single crystal of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol, formulated as C15H15N1O2, reveals that the structure is adopted to its E configuration about the azomethine C=N double bond. The compound adopts a enol-imine tautomeric form with a strong intramolecular O-H center dot center dot center dot N hydrogen bond. The single crystal X-ray diffraction analysis at 296 K crystallizes in the monoclinic space group P21/c with a = 13.4791(11) angstrom, b = 6.8251(3) angstrom, c = 18.3561( 15) angstrom, alpha = 90 degrees, beta= 129.296(5)degrees, gamma = 90 degrees and Z = 4. Comprehensive theoretical and experimental structural studies on the molecule have been carried out by FT-IR and UV-vis spectrometry. Optimized molecular structure and harmonic vibrational frequencies have been investigated by DFT/B3LYP method with 6-31G(d,p) basis set. Stability of the molecule, hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed by using natural bond orbital (NBO) analysis. Electronic structures were discussed by TD-DFT method and the relocation of the electron density were determined. The energetic behavior of the title compound has been examined in solvent media using polarizable continuum model (PCM). Molecular electrostatic potential (MEP), Mulliken population method and natural population analysis (NPA) have been studied. Nonlinear optical (NLO) properties were also investigated. In addition, frontier molecular orbitals analysis have been performed from the optimized geometry. An ionization potential (I), electron affinity (A), electrophilicity index (omega), chemical potential (mu), electronegativity (chi), hardness (eta), and softness (S), have been investigated. (C) 2014 Elsevier B.V. All rights reserved.Öğe Experimental (X-ray, FT-IR and UV-vis spectra) and theoretical methods (DFT study) of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol (vol 128, pg 748. 2014)(Pergamon-Elsevier Science Ltd, 2014) Demircioglu, Zeynep; Albayrak, Cigdem; Buyukgungor, Orhan[No abstract available]Öğe Experimental and density functional theory (DFT) studies on (E)-2-Acetyl-4-(4-nitrophenyldiazenyl) phenol(Elsevier, 2011) Yazici, Serap; Albayrak, Cigdem; Gumrukcuoglu, Ismail; Senel, Ismet; Buyukgungor, OrhanA suitable single crystal of (E)-2-Acetyl-4-(4-nitrophenyldiazerwl) phenol, formulated as C14H11N3O4, (I), reveals that the structure is adopted to its E configuration and molecules are linked by C-H center dot center dot center dot O hydrogen bonds. The title compound which has been characterized by IR, UV and single crystal X-ray diffraction analysis at 150K crystallizes in the monoclinic space group C 2/c with a= 12.8640(8) angstrom, b = 7.3264(3) angstrom, c = 26.9330(17) angstrom, alpha = 90 degrees, beta = 93.052(5)degrees, gamma = 90 degrees, Z = 7. The molecular structure and geometry have also been optimized using B3LYP density functional theory method employing the 6-31G (d, p) basis set. To acquire lowest- energy molecular conformation of the title molecule, the selected torsion angle is varied every 10 and molecular energy profile is calculated from -180 degrees to +180 degrees. Furthermore, the molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis, nonlinear optical properties (NLO) and thermodynamic properties for the title molecule are also described from the computational process. (c) 2010 Elsevier B.V. All rights reserved.Öğe Experimental and DFT Studies of N-2-Methoxyphenyl-2-oxo-5-nitro-1-benzylidenemethylamine: In Gas Phase and Solvent Media.(Int Union Crystallography, 2009) Tanak, Hasan; Yavuz, Metin; Buyukgungor, Orhan; Ersahin, Ferda; Agar, Erbil[No abstract available]Öğe Experimental and quantum chemical computational study of (E)-1-[5-(3,4-dimethylphenyldiazenyl)-2-hydroxyphenyl]ethanone(Pergamon-Elsevier Science Ltd, 2012) Yazici, Serap; Albayrak, Cigdem; Gumrukcuoglu, Ismail Erdem; Senel, Ismet; Buyukgungor, OrhanIn this work, the azo dye, (E)-1-[5-(3,4-dimethylphenyldiazenyl)-2-hydroxyphenyl]ethanone, has been synthesized and characterized by IR. and X-ray single-crystal determination. In the theoretical calculations, the stable structure geometry of the isolated molecule in gas phase was investigated under the framework of the density functional theory (B3LYP) with 6-31G (d, p). To designate lowest energy molecular conformation of the title molecule, the selected torsion angle was varied every 10 degrees and the molecular energy profile was calculated from - 180 degrees to +180 degrees. Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis, and thermodynamic properties were described from the computational process. In addition to these calculations, we were investigated solvent effects on the nonlinear optical properties (NLO) of the title compound. (C) 2012 Elsevier B.V. All rights reserved.
