Yazar "Kara, Hulya" seçeneğine göre listele

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    Synthesis, crystal structure, spectroscopic studies and Ab-initio calculations on third-order optical nonlinearity of a five-coordinate chloroiron(III) complex
    (WORLD SCIENTIFIC PUBL CO PTE LTD, 2007) Karakas, Asli; Donmez, Emine; Kara, Hulya; Elmali, Ayhan
    A five-coordinate chloroiron(III) complex has been synthesized and characterized by X-ray diffraction analysis and UV-Vis spectroscopy. The maximum one-photon absorption ( OPA) wavelengths recorded by both linear optical measurements and quantum mechanical computations using the configuration interaction ( CI) method are estimated to be shorter than 400 nm in the UV region, showing good optical transparency to visible light. To investigate the microscopic third-order nonlinear optical ( NLO) behavior of the title compound, 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 the time- dependent Hartree - Fock ( TDHF) method. The ab- initio calculation results with non- zero values on ( hyper) polarizabilities indicate that the synthesized molecule might possess microscopic third- order NLO phenomena.
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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.
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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.
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    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.
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    Third-order nonlinear optic and optical limiting properties of a MN(III) transition metal complex
    (WORLD SCIENTIFIC PUBL CO PTE LTD, 2007) Karakas, Asli; Elmali, Ayhan; Yahsi, Yasemin; Kara, Hulya
    N,N'-bis(5-bromosalicylidene)propane-1,2-diamine-O,O',N,N')-manganese(III) chloride transition metal complex has been synthesized and characterized by elemental analysis and UV-vis spectroscopy. Its crystal structure has been determined using X-ray diffraction analysis. To provide an insight into the optical limiting (OL) behavior of the title compound, the third-order nonlinear optical (NLO) properties, one-photon absorption (OPA) and two-photon absorption (TPA) characterizations have been theoretically investigated by means of the time-dependent Hartree-Fock (TDHF), AM1 and configuration interaction (CI) methods, respectively. According to ab initio calculation results, the examined molecule exhibits second hyperpolarizabilities (gamma) with non-zero values at the positions of TPA peaks, implying microscopic third-order optical nonlinearity. The maximum OPA wavelengths recorded by linear optical experiment and quantum mechanical computations are estimated in the UV region to be shorter than 400 nm, showing good optical transparency to the visible light. The TPA cross-sections (delta(omega)) at lambda((2))(max) values indicate that the synthesized compound might possess OL phenomena, which are in accord with the experimental observations on the manganese complexes in the literature.