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    Characterization of pentacarbonyl(4-methylpyridine)chromium(0) complex using density functional theory (DFT) and Hartree-Fock (HF) computational methods
    (Pergamon-Elsevier Science Ltd, 2011) Morkan, İzzet Amour; Morkan, Ayse Uztetik
    The optimized molecular structure, atomic charges, vibrational frequencies, thermodynamic properties, nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-Vis) spectral data of pentacarbonyl(4methylpyridine)chromium(0) complex have been investigated by performing ab initio Hartree-Fock (HF) and density functional theory, B3LYP. B3PW91 and BE1PBE methods with 6-311G, 6-311+G(3d,3p) and 6-31G(d,p) basis set. The calculated NMR data at 6-311G basis set, vibrational frequencies at 6-311+G(3d,3p) basis set and the optimized geometric bond lengths and bond angles at 6-31G(d,p) basis set are in good agreement with the corresponding experimental values. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) have been simulated. In addition, the transition state and energy band gap and infrared intensities have also been reported. (C) 2011 Elsevier B.V. All rights reserved.
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    Cycloaddition reactions of (eta(6)-tropone) tricarbonylmetal(0) complexes of group 6 metals with alkynes
    (Inst Organic Chem And Biochem, 2002) Morkan, İzzet Amour; Morkan, Ayşe Üztetik
    (eta(6)-Cyclohepta-2,4,6-trien-1-one) tricarbonylmetal(0) complexes of chromium (2a), molybdenum (2b), and tungsten (2c) are formed when tris( acetonitrile) tricarbonylchromium(0), mo-lybdenum(0), and tungsten(0), respectively, are treated photochemically with tropone (cyclohepta-2,4,6-trien-1-one) 1. UV photolysis of 2a-2c and RCequivalent toCR' (R=R'=Ph, Me3Si, Et; R=Ph, R'=Me3Si) in toluene gives the [6+2] cycloadducts, (eta(4), eta(2)-8,9-diphenylbicyclo-[4.2.1] nona-3,5,8-trien-1-one) tricarbonylmetal(0) 3a-3c,(eta(4), eta(2)-8,9-bis(trimethylsilyl) bicyclo[4.2.1] nona-3,5,8-trien-1-one) tricarbonylmetal(0) 4a-4c,(eta(4), eta(2)-8,9-diethylbicyclo[4.2.1] nona-3, 5,8-trien-1-one) tricarbonylmetal(0) 5a-5c, and (eta(4), eta(2)-8-phenyl-9-(trimethylsilyl) bicyclo-[4.2.1] nona-3,5,8-trien-1-one) tricarbonylmetal(0) 6a-6c. Compounds 2a-2c, 3a-3c, 4a-4c, 5a-5c, and 6a-6c were purified by chromatography, recrystallized and isolated as analytically pure crystalline solids in moderate yields and characterized by mass, IR, and NMR spectroscopy. Pure organic heterobicyclotriene ligands 7a, 8a, 9a, and 10a were isolated from 3a, 4a, 5a, and 6a, respectively, by treatment with cerium(IV) ammonium nitrate (R=R'=Me3Si; R=Ph, R=Me3Si) or by heating in toluene (R=R'=Ph, Et). It was not possible to isolate the bicyclic complexes resulting from the reactions of 2a-2c with terminal alkynes like phenylacetylene.
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    High order cycloaddition reactions of M(CO)3-coordinated N-cyanoazepine with alkynes; M: Cr, Mo, W
    (2002) Morkan, İzzet Amour
    Tricarbonyl(N -cyanoazepine)metal(0) complexes of chromium (2a), molybdenum (2b) and tungsten (2c) are formed when tricarbonyl-tris(acetonitrile)chromium(0), -molybdenum(0) and -tungsten(0), respectively, are treated photochemically with N-cyanoazepine (1). The resulting complexes are purified. UV photolysis of Cr(CO)3(?6-N-cyanoazepine) (2a) and RC=CR (R: Ph, SiMe3) in toluene gives the [6+2]cycloadducts, tricarbonyl{?4:2-7,8-diphenyl-9- N-cyano-9-azabicyclo[4.2.1]-nona-2,4,7-triene}chromium(0), chromium(0), [(?4:2-C8H6N(CN)(SiMe3)2)Cr(CO)3] (3b). Like 2a-c, these new bicyclic compounds were purified by chromatography, recrystallized and isolated as analytically pure crystalline solids in moderate yields and characterized by mass, IR and NMR spectroscopy. The heterobicyclotrienes (4a,b) are isolated from (3a,b) by treatment with cerium(IV) ammonium nitrate (R=SiMe3 ) or by heating in toluene (R=Ph). © 2002 Published by Elsevier Science B.V.
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    Pentacarbonyl(2,6-diaminopyridine)chromium(0): synthesis and molecular structure
    (Elsevier Science Sa, 2004) Morkan, İzzet Amour; Güven, Kutalmış; Özkar, Saim
    Photolysis of hexacarbonylchromium(0) in the presence of 2,6-diaminopyridine in toluene solution at 10 degreesC yields pentacarbonyl(2,6-diaminopyridine)chromium(0), which could be isolated from solution as plate-like crystals and fully characterized by using the single crystal X-ray diffractometry and MS, IR, H-1 and C-13 NMR spectroscopy. The complex was found to have the 2,6-diaminopyridine ligand bonded to the chromium atom through one of the NH2 groups. A single crystal X-ray structure of the complex reveals that the coordination sphere around the chromium atom is a slightly distorted octahedron, involving five carbonyls and one 2,6-diaminopyridine ligand. Because of the steric requirement of 2,6-diaminopyridine the four equatorial carbonyl groups are bended away from the N-donor ligand. The pyridine plane makes an angle of 112.9(3)degrees with the OC-Cr-N bond axis. The Cr-C distances have values between 1.833(7) and 1.935(7) Angstrom. The Cr-N distance is 2.236(5) Angstrom.
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    Photochemical synthesis and identification of tetracarbonyl-bis(olefin)metal(0) complexes of group VI B elements
    (Verlag der Zeitschrift fur Naturforschung, 2000) Morkan, İzzet Amour; Uztetik-Morkan, Ayşe
    Photolysis of hexacarbonyl metal(0) or tetracarbonyl-bis(1,3-butadiene)metal(0) (metal: chromium, molybdenum, tungsten) in the presence of tetracyanoethylene, TCNE, or fumaronitrile , FN, at room temperature yields trans-bis(?2-tetracyano-ethylene)tetracarbonyl-chromium(0) (1), -molybdenum(0) (2), -tungsten(0) (3) and trans-bis(fumaronitrile)tetracarbonyl-chromium(0) (4), -tungsten(0) (5) complexes. The complexes were purified by chromatography and recrystallization and characterized by IR , 1H, 13C NMR and mass spectroscopies. It is shown that two tetracyanoethylene ligands are symmetrically bonded to the M(CO)4 moiety through their carbon-carbon double bond in the form of ?2-TCNE . The two fumaronitrile ligands are bonded to the central atom through their nitrogen atoms. The spectral data are discussed in terms of metal -? ligand ?-interaction.
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    Photoinduced reactions of Cr(CO)(3)-coordinated N-cyanoazepine: [6+4] cycloaddition with conjugated dienes
    (Springer, 2003) Morkan, İzzet Amour; Uztetik-Morkan, Ayşe
    The tricarbonyl(N-cyanoazepine)chromium(0) complex (2) is formed when (MeCN)(3)Cr(CO)(3) is treated photochemically with N-cyanoazepine (1). U.v photolysis of Cr(CO)(3)(eta(6)-N-cyanoazepine)chromium(0) (2) and conjugated dienes [1,3-butadiene (3), trans-1,3-pentadiene (4), trans,trans-2,4-hexadiene (5)] in PhMe give the [6+4]cycloadducts, tricarbonyl{eta(4:2)-11-N-cyano-11-azabicyclo[4.4.1]-undeca-2,4,8-triene}chromium(0) complexes (6-8). The pi-complex (2) and these new bicyclic compounds (6-8) were purified by chromatography, recrystallized, isolated as analytically pure crystalline solids in moderate yields and characterized by mass, i.r. and n.m.r. spectroscopy. The heterobicyclotrienes, 11-N-cyano-11-azabicyclo[4.4.1]undeca-2,4,8-triene (9-11), were isolated from the complexes (6-8) by heating in PhMe, and their structures were assigned by the same spectroscopic methods.
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    Structural, morphological, and magnetic characterization of bulk and thin films Y3Al5-xFexO12 (YAIG): from the perspective of aqueous sol-gel processing
    (Taylor & Francis Inc, 2017) Opuchovic, Olga; Cülünlü, Serdar; Morkan, Ayşe Uztetik; Morkan, İzzet Amour; Niznansky, Daniel
    An aqueous sol-gel method was used for the preparation of bulk Y3Al5-xFexO12 (yttrium aluminum-iron garnet, YAIG) with the composition of x=0.0, 1.0, 2.0, 2.5, 3.0, 4.0, 5.0 and thin films with the composition of x=0, 3.0, 4.0, 5.0. The dip-coating technique was used for the preparation of Y3Al5-xFexO12 films on a silicon (Si) substrate. The phase composition and surface morphology of both bulk and coatings were determined and compared. The synthesized powder samples were investigated by X-ray diffraction analysis, infrared spectroscopy, scanning electron microscopy, and Mossbauer spectroscopy. The data provide evidence that some sol-gel-derived powder specimens consist of magnetically ordered component, while others show paramagnetic behavior depending on the composition of the product. It was also shown that sol-gel processing route could be successfully used for the preparation of mixed-metal YAIG thin films.
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    Synthesis and spectroscopic characterization of group 6 pentacarbonyl(4-substituted pyridine)metal(0) complexes
    (Springer, 2007) Tuç, Çiğdem; Morkan, İzzet Amour; Özkar, Saim
    Carbonyl-metal (M:Cr, Mo, W) derivatives of 4-substituted pyridines [4-methylpyridine (4-mp), 4-tert-butylpyridine (4-tbp) and 4-dimethylaminopyridine (4-dmap)] where the metal center is bonded to the nitrogen atom of the substituted pyridine ring are described. The organometallic complexes, M(CO)(5)L, were synthesized by either the direct reaction of the metal hexacarbonyls or by the thermal substitution of M(CO)(5)(THF) with the pyridine ligands; 4-methylpyridine (1), 4-tert-butylpyridine (2), 4-dimethylaminopyridine (3). The reported complexes were purified by column chromatography and recrystallization. The complexes were all characterized in solution by elemental analysis, MS, ir ,(1) H-nmr and (13) stopC-nmr spectroscopies.
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    Synthesis, crystal structure, spectroscopic investigations, thermal behavior and DFT calculations of pentacarbonyl(2-methylpyrazine)chromium(0)
    (Pergamon-Elsevier Science Ltd, 2012) Morkan, İzzet Amour; Çelik, Derya; Morkan, Ayşe Uztetik; Güven, Kutalmış
    Pentacarbonyl(2-methylpyrazine)chromium(0) [Cr(CO)(5)(2mpyz)], complex was isolated from its n-hexane solution as orange plate-like crystals which were characterized by IR, NMR spectroscopies and X-ray crystallography. The crystallographic results show that the complex was crystallized in the monoclinic system with the unit cell parameters of a = 7.176 (5), b = 12.045 (3), c = 14.461 (3)angstrom, beta=90.44 (3)degrees and space group 2/M. The single crystal structure of the complex shows the bonding of chromium metal to 2-methylpyrazine through the less sterically hindered nitrogen-4 lone pair. The pyrazine ring plane makes an angle of 179.58 degrees (19) with CO-Cr-N bond axis. The four carbonyl groups are slightly bent away from pyrazine with the angle of 91.28 degrees (17) for C-s-Cr-N1 bond axis. The DFT calculations run out using the Gaussian 03 PC program show good agreement with the experimental results. The thermal properties of the complex were also investigated by differential thermal analysis and thermogravimetry techniques. (C) 2012 Elsevier B.V. All rights reserved.
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    Synthesis, crystal structure, thermal behavior and IR characterization of pentacarbonyl(4-methylpyridine)chromium(0) complex
    (Springer/Plenum Publishers, 2008) Morkan, İzzet Amour; Morkan, Ayşe Uztetik; Tuç, Çiğdem; Kendi, Engin
    Pentacarbonyl(4-methylpyridine)chromium(0) complex was isolated from n-hexane solution as yellow plate-like crystals and characterized by using X-ray crystallography. It crystallizes in the orthorhombic system with the space group Cmcm and Z = 4. The unit cell parameters are a = 11.737(1) angstrom, b = 12.857(2) angstrom, c = 8.465(1) angstrom. The single crystal X-ray structure of the complex shows that the coordination sphere around the chromium central atom is slightly distorted octahedron, involving the 4-methylpyridine (4-mp), ligand as a monodentate N-donor ligand and five carbonyl groups. The four equatorial CO groups in the complex, with the Cr-C2 distance of 1.886 angstrom, are slightly bent away from the 4-methylpyridine ligand with the N-Cr-C2 angle of 91.69. The pyridine ring plane makes an angle of 135.17 with the Cr-N-CO bond axis. The thermal analysis (differential thermal analysis and thermal gravimetry) and IR spectra of the complex indicated that the compound undergoes complete decomposition to form the Cr2O3 as the final decomposition product.