Yazar "Elmali, A" seçeneğine göre listele

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    The investigation of nonlinear optical properties of N-(3-fluorophenyl)naphthaldimine
    (ELSEVIER SCIENCE BV, 2005) Unver, H; Karakas, A; Elmali, A; Durlu, TN
    A new ligand N-(3-fluorophenyl)naphthaldimine (C17H12NOF) has been synthesized. The physical properties and structure of this ligand have been characterized by X-ray diffraction analysis, elemental analysis, FT-IR, H-1-NMR and UV-visible spectroscopies. It is found that the title compound has solvatochromic behavior in the UV and visible regions, implying non-zero microscopic first hyperpolarizability. The electric dipole moment (mu) and the first hyperpolarizability (beta) values of the investigated molecule have been computed using ab initio quantum mechanical calculations (finite field second-order Moller Plesset perturbation theory). The calculation results also reveal that the synthesized molecule might have microscopic nonlinear optical (NLO) behavior with non-zero values. (C) 2004 Elsevier B.V. All rights reserved.
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    Nonlinear optical properties of bis[(p-bromophenyl-salicylaldiminato)chloro]iron(III) and its ligand N-(4-bromo)-salicylaldimine
    (ELSEVIER SCIENCE BV, 2005) Elmali, A; Karakas, A; Unver, H
    A new Schiff base metal complex bis[(p-bromophenyl-salicylaldiminato)chloro]iron(III) [Cl(C(13)H(9)NOBr)(2)Fe] and its ligand (N-(4-bromo)-salicylaldimine) have been synthesized. The title complex and its ligand have been characterized by elemental analysis, IR technique, and UV-Vis spectroscopy. It is found that the investigated compounds have solvatochromic behavior, implying rather well molecular first hyperpolarizability. The ab initio molecular orbital calculations (FF MP2) of the synthesized compounds have been carried out to compute the electric dipole moment (D) and the first hyperpolarizability (beta) values. (C) 2004 Elsevier B.V. All rights reserved.
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    Nonlinear optical properties of some derivatives of salicylaldimine-based ligands
    (ELSEVIER SCIENCE BV, 2004) Karakas, A; Elmali, A; Unver, H; Svoboda, I
    A series of potential nonlinear optical (NLO) compounds, (-OH) and (-Cl) substituted derivatives of salicylaldimine-based ligands 1-6 (Fig. 2), was designed and synthesized. Compounds 1 and 2 were characterized by X-ray diffraction analysis, elemental analysis, IR, H-1-NMR, C-13-NMR and UV-Visible spectroscopies. The electric dipole moments (mu) and the first hyperpolarizabilities (beta) of the compounds 1-6 were calculated using ab-initio quantum calculations (finite field Moller Plesset perturbation theory). The calculation results reveal that the substituent positions play a significant role in NLO properties of these compounds. (C) 2004 Elsevier B.V. All rights reserved.
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    Nonlinear optical properties, spectroscopic studies and structure of 2-hydroxy-3-methoxy-N-(2-chloro-benzyl)-benzaldehyde-imine
    (ELSEVIER SCIENCE BV, 2004) Unver, H; Karakas, A; Elmali, A
    2-Hydroxy-3-methoxy-N-(2-chloro-benzyl)-benzaldehyde-imine (C(15)H(14)O(2)NCl) has been synthesized and then, characterized by elemental analysis, X-ray analysis, IR, (1)H-NMR, and UV-Visible spectroscopies. The whole molecule is not planar. Each molecule contains a strong O-H(...)N hydrogen bond. To investigate the microscopic second-order nonlinear optical mechanism, the ab initio calculations of the electric dipole moments (mu) and the first hyperpolarizabilities (beta) on model ligand have been performed using the FF MP2 method. The ab initio results reveal that the title compound has relatively good nonlinear optical properties. (C) 2004 Elsevier B.V. All rights reserved.
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    Nonlinear optical properties, synthesis, structures and spectroscopic studies of N-(4-nitrobenzylidene)-o-fluoroamine and N-(3-nitrobenzylidene) p-fluoroamine
    (PERGAMON-ELSEVIER SCIENCE LTD, 2005) Karakas, A; Elmali, A; Unver, H; Svoboda, I
    N-(4-nitrobenzylidene)-o-fluoroamine (1) and N-(3-nitrobenzylidene)-p-fluoroamine (2) have been synthesized. The crystal structures of both compounds have been defined by X-ray diffraction analysis, and characterized by FT-IR and UV-visible instrumental methods. The recorded spectrum by UV-visible spectroscopy for the investigated compounds show good transparency in the visible region, and have solvatochromic behavior in the UV region, implying nonzero microscopic first hyperpolarizability. We also report ab initio quantum chemical calculations of the electric dipole moments (mu) and the first hyperpolarizabilities (beta) of the studied compounds. Our results suggest that the investigated ligands might have microscopic nonlinear optical (NLO) behavior with nonzero values. (c) 2004 Published by Elsevier B.V.
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    Schiff bases with various donor-acceptor substituents and regulating groups as non-linear optical materials: ab initio quantum mechanical calculations
    (ELSEVIER SCIENCE BV, 2004) Karakas, A; Unver, H; Elmali, A
    The electric dipole moments (mu), first (beta) and second (gamma) hyperpolarizabilities of a series of Schiff bases with different donor-acceptor substituents and regulating groups (R) were calculated using ab initio quantum mechanical methods. The hyperpolarizabilities obtained have been found to be rather adequate for assessing connectivities between the electronegativities of substituents and regulating groups and non-linear optical properties. (C) 2004 Elsevier B.V. All rights reserved.
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    Structural and magnetic properties of Al doped Co-Ag granular films: temperature dependence of magnetoresistance
    (ELSEVIER SCIENCE BV, 2004) Oksuzoglu, RM; Elmali, A; Henn, R; Fuess, H; Hahn, H
    The correlation between the structure, the magnetic and magnetotransport properties of sputter-deposited (Co90Al10)(x)Ag100-x granular films (19 less than or equal to x less than or equal to 45) are investigated. For an (Co90Al10) content of about 28% the magneto resistance (MR) ratio of the films reach its highest value of 6%. Al doping reduces the MR ratio in CoAg films, however, leads to a almost constant MR ratio against post annealing up to 773 K in (Co90Al10)(28)Ag-72 granular films, although the film structure is affected by annealing, respectively. According to magnetization measurements, superparamagnetic cobalt grains in the as-deposited (Co90Al10)(28)Ag-72 sample show after annealing up to 773 K both superparamagnetic and ferromagnetic behaviour. Annealing at 823 K causes a domain formation of large ferromagnetic grains with strong correlation. (C) 2004 Elsevier B.V. All rights reserved.
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    Study on the second order optical properties of N-(2,4-dichloro)-salicylaldimine
    (VERLAG Z NATURFORSCH, 2005) Karakas, A; Unver, H; Elmali, A; Svoboda, I
    N-(2,4-Dichloro)-salicylaldimine was synthesized, characterized by elemental analysis, FT-IR, and UV-visible spectroscopy, and its crystal structure was determined. The title compound is almost planar and contains short intramolecular O-H center dot center dot center dot N hydrogen bonds [O1-N1 2.601(1) A]. It remains transparent in the visible region and has solvatochromic behavior in the UV region in the range 198 349 nm, implying non-zero microscopic first hyperpolarizability. The ab-initio quantum mechanical calculations (finite field second-order Moller Plesset perturbation theory) of the studied compound have been carried out to compute the electric dipole moment (mu) and the first hyperpolarizability (beta) values. The ab-initio results also show that this ligand might have microscopic nonlinear optical behavior with non-zero values.