Yazar "Unver, Huseyin" seçeneğine göre listele

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  • Küçük Resim Yok
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    Crystal structure and nonlinear optical behavior of N-(2 or 3-nitrobenzalidene)2,4-dimethylaniline
    (INT UNION CRYSTALLOGRAPHY, 2008) Elmali, Ayhan; Karakas, Asli; Unver, Huseyin
    [Abstract not Available]
  • Küçük Resim Yok
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    Crystal structure and nonlinear optical properties of n-(3-hydroxybenzalidene)4-bromoaniline
    (INT UNION CRYSTALLOGRAPHY, 2008) Unver, Huseyin; Karakas, Asli; Elmali, Ayhan
    [Abstract not Available]
  • Küçük Resim Yok
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    The investigation of electronic properties and microscopic second-order nonlinear optical behavior of 1-salicylidene-3-thio-semicarbazone
    (WORLD SCIENTIFIC PUBL CO PTE LTD, 2007) Karakas, Asli; Unver, Huseyin; Elmali, Ayhan
    To investigate the microscopic second-order nonlinear optical (NLO) behavior of the 1-salicylidene-3-thio-semicarbazone Schiff base compound, the electric dipole moments (mu), linear static polarizabilities (alpha) and first static hyperpolarizabilites (beta) have been calculated using finite field second-order Moller-Plesset perturbation (FF MP2) theory. The ab-initio results on (hyper) polarizabilities show that the investigated molecule might have microscopic NLO properties with non-zero values. To understand the NLO behavior in the context of molecular orbital structure, we have also examined the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and the HOMO-LUMO gap in the same theoretical framework as the (hyper)polarizability calculations. In addition to the NLO properties, the electronic transition spectra have been computed using a semi-empirical method (ZINDO). ZINDO calculation results show that the electronic transition wavelengths have been estimated to be shorter than 400 nm.
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    Linear optical transmission measurements and computational study of linear polarizabilities, first hyperpolarizabilities of a dinuclear iron(III) complex
    (PERGAMON-ELSEVIER SCIENCE LTD, 2007) Karakas, Ash; Elmali, Ayhan; Unver, Huseyin
    The optical transmission spectral study of a dinuclear metal complex [FeL(MeOH)Cl](2) (L = N-(5-methylphenyl)-3-methoxysaticylaldimine) has been carried out. The linear optical characterization shows that this molecule has transparency in the visible range. To understand linear optical and microscopic second-order nonlinear optical (NLO) behavior of the compound, we have computed the electric dipole moment (mu) and dispersion-free first hyperpolarizabilities (beta) using Finite Field second-order Moller-Plesset perturbation (FF MP2) procedure; and also dispersion-free linear polarizabilities (alpha), frequency-dependent linear polarizabilities within the linear optical spectrum and first hyperpolarizabilities lambda = 730-1050 and 1000-1400 ran wavelength areas using time-dependent Hartree-Fock (TDHF) method. The ab-initio calculation results reveal that the examined complex might have linear optical and microscopic NLO behavior with non-zero values. (C) 2006 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
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    Spectroscopic properties of 4-halo-2-(4-chloro-phenyliminomethyl)phenol and 4-halo-2-(4-bromophenyliminomethyl)phenol
    (ASIAN JOURNAL OF CHEMISTRY, 2006) Unver, Huseyin; Karakas, Asli; Colak, Naki; Cakir, Bekir; Yuksel, Huseyin; Zengin, D. Mehmet
    4-Halo-2-(4-chlorophenyliminomethyl)phenol and 4-halo-2-(4bromophenylin-dnomethyl)phenol have been synthesized and then characterized by elemental analysis, FTIR, (1)H NMR and UV-Vis spectroscopy. The spectroscopic data of all the investigated compounds revealed that the tautomeric equilibrium of the studied Schiff bases favour the enol form.
  • Küçük Resim Yok
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    Spectroscopic Study and Third-order Nonlinear Optical Behavior of N-(2-Hydroxy-4-methoxybenzylidene)-3-nitroaniline.
    (INT UNION CRYSTALLOGRAPHY, 2009) Unver, Huseyin; Karakas, Asli; Elmali, Ayhan; Durlu, Tahsin Nuri
    [Abstract not Available]
  • Küçük Resim Yok
    Öğe
    Static and dynamic second hyperpolarizabilities of [FeL(MeOH)Cl](2) (L = N-(5-methylphenyl)-3-methoxysalicylaldimine)
    (ELSEVIER SCIENCE BV, 2006) Karakas, Asli; Unver, Huseyin; Elmali, Ayhan
    To investigate microscopic third-order nonlinear optical (NLO) behavior of the [FeL(MeOH)Cl](2) (L = N-(5-methylphenyl)-3-methoxysalicylaldimine) metal complex, we have computed both dispersion-free (static) and also frequency-dependent (dynamic) linear polarizabilities (alpha) and second hyperpolarizabilities (gamma) at lambda = 825-1125 nm and 1050-1600 nm wavelength areas using time-dependent Hartree-Fock (TDHF) method. According to ab initio calculation results, the title molecule exhibits second hyperpolarizabilities with non-zero values, implying microscopic third-order NLO behavior. (c) 2006 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
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    Structure, Spectroscopic Study and ab initio Calculations on Third-order Nonlinear Optical Behavior of N-(2-Hydroxy-4-methoxybenzylidene)-3-nitroaniline
    (VERLAG Z NATURFORSCH, 2008) Unver, Huseyin; Karakas, Asli; Elmali, Ayhan; Durlu, T. Nuri
    N-(2-hydroxy-4-methoxybenzylidene)-3-nitroaniline (1) has been synthesized and characterized by X-ray diffraction analysis, FTIR and (1)H NMR spectroscopy. The maximum one-photon absorption (OPA) wavelengths recorded by quantum mechanical computations using a configuration interaction (CI) method are estimated in the UV region to be shorter than 450 nm, showing good optical transparency to the visible light. We have computed both dispersion-free (static) and also frequency-dependent (dynamic) linear polarizabilities (alpha) and second hyperpolarizabilities (gamma) by using the time-dependent Hartree-Fock (TDHF) method to provide an insight into the microscopic third-order nonlinear optical (NLO) behavior of the title compound. The ab initio calculation results with non-zero values on (hyper)polarizabilities indicate that the synthesized molecule might possess microscopic third-order NLO phenomena.
  • Küçük Resim Yok
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    Synthesis, molecular structure, spectroscopic studies and second-order nonlinear optical behaviour of N,N '-(2-hydroxy-propane-1,3-diyl)-bis (5-nitrosalicylaldiminato-N,O)-copper(II)
    (PERGAMON-ELSEVIER SCIENCE LTD, 2007) Donmez, Emine; Kara, Hulya; Karakas, Asli; Unver, Huseyin; Elmali, Ayhan
    N,N'-(2-Hydroxy-propane-1,3-diyl)-bis(5-nitrosalicylaldiminato-N,O)-copper(II) has been synthesized. The crystal structure has been determined by X-ray diffraction analysis, and linear optical characterization has been determined by UV-vis spectroscopy. It was found that the molecule under investigation has solvatochromic behaviour in the UV region, implying non-zero microscopic first hyperpolarizability. To reveal the microscopic nonlinear optical (NLO) properties, the static first hyperpolarizabilities (beta) and the electric dipole moments (mu) were evaluated by using the ab initio finite field (FF) method. According to the results of the FF calculations, the synthesized compound exhibits non-zero beta values, and it might have microscopic NLO behaviour. (c) 2006 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
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    Synthesis, spectroscopic studies and nonlinear optical behavior of N,N '-bis(2-hydroxy-1-naphthylmethylidene)-1-methyl-1, 2-diaminoethane-N,N ',O,O '-nickel(II)
    (ELSEVIER SCIENCE BV, 2006) Unver, Huseyin; Elmali, Ayhan; Karakas, Ash; Kara, Hulya; Donmez, Emine
    A Schiff base complex N,N'-bis(2-hydroxy-1-naphthylmethylidene)-1-methyl-1,2- diaminoethane-N,N',O,O'-nickel(II) has been synthesized. The title compound has been characterized by FT-IR and UV-vis spectroscopies. The UV-vis experiments indicate that the compound has solvatochromism in the UV region, implying non-zero molecular first hyperpolarizability. To investigate microscopic second-order nonlinear optical (NLO) behavior of the examined complex, the electric dipole moments (mu) and the first static hyperpolarizabilities (beta) were computed using Finite Field second-order Moller Plesset (FF MP2) perturbation procedure. According to ab initio quantum mechanical calculations, the title complex exhibits non-zero P values, revealing microscopic second-order NLO behavior. (c) 2006 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Synthesis, structure, spectroscopic studies and ab-initio calculations on first hyperpolarizabilities of NN '-bis(2-hydroxy-1-naphthyl-methylidene)-1-methyl-1,2-diaminoethane-N,N ',O,O '-copper(II)
    (WALTER DE GRUYTER GMBH, 2006) Karakas, Ash; Elmali, Ayhan; Unver, Huseyin; Kara, Hulya; Yahsi, Yasemin
    N,N'-Bis(2-hydroxy-1-naphthylmethylidene)-1-methyl-1,2-diaminoethane-N,N',O,O'-copper(II) has been synthesized, and characterized by FT-IR and UV/vis spectroscopies. Its crystal structure has been determined by X-ray diffraction analysis. The maximum absorption wavelengths recorded by linear optical experiments are estimated in the UV region to be shorter than 450 nm, showing good optical transparency to the visible light. It may thus possess first hyperpolarizabilities with non-zero values for nonlinear optical (NLO) applications. Ab-initio quantum chemical calculations of the electric dipole moments (mu) and the first static hyperpolarizabilities (0) were carried out. The computational results suggest that the complex may indeed have microscopic NLO behavior with non-zero values.