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Öğe 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]Öğe 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]Öğe Electric Dipole Moment and Static First Hyperpolarizability Values of 4-(2-Pyridylazo)resorcinol: High Accuracy Density Functional Theory Computations(IEEE, 2011) Karakas, Asli; Ayhan, Elif4-(2-Pyridylazo) resorcinol (1) has been designed. Due to the shape of the molecule, nonlinear optical (NLO) properties are expectable and can be more or less accurately predicted. To reveal the potential for second-order NLO phenomena, the electric dipole moment (mu) and dispersion-free first hyperpolarizabilities (beta) have been evaluated by density functional theory (DFT) quantum chemical computations at B3LYP/6 - 311+G(d, p) level. According to the calculation results, the title compound exhibits non-zero static first hyperpolarizability values, and it might have relatively good second-order NLO behaviour.Öğe 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, AyhanTo 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.Öğe THE INVESTIGATION OF SECOND-ORDER NONLINEAR OPTICAL PROPERTIES OF P-NITROPHENYLAZOANILINE: SECOND HARMONIC GENERATION AND AB INITIO COMPUTATIONS(WORLD SCIENTIFIC PUBL CO PTE LTD, 2012) Karakas, Asli; Koc, Ziya Erdem; Fridrichova, Michaela; Nemec, Petr; Kroupa, Janp-nitrophenylazoaniline (1) belongs to the family of compounds with conjugated bonds and delocalized pi-electrons, structurally similar to the well known push-pull compound Disperse Red 1 (DR1).(1) Due to the assembly of the molecule, nonlinear optical (NLO) properties are expectable and can be more or less accurately predicted. To estimate the potential for second-order NLO properties, the electric dipole moment (mu), dispersion-free dipole polarizabilities (alpha) and first hyperpolarizabilities (beta) have been determined by density functional theory (DFT) quantum chemical calculations at B3LYP/6-311+G(d,p) level. According to the computation results, the synthesized compound exhibits non-zero beta values and it might have second-order NLO behavior. Title compound has been synthesized and characterized by FT-IR, H-1-NMR and UV-Vis spectroscopies. The maximum one-photon absorption (OPA) wavelengths were estimated to be shorter than 450nm by quantum mechanical computations using the configuration interaction (CI) method. The same result was achieved by UV-Vis spectra measurements, whereas the compound exhibited good optical transparency to the visible light. Quantitative measurements of second harmonic generation (SHG) at 800nm and 1064nm have been performed. The relative efficiency comparable with that of KDP (kalium diphosphate) has been observed with the exciting wavelength of 1064 nm, while the other wavelength led to strong absorption of produced light by the sample. In the following more detailed study on frequency-dependent first hyperpolarizabilities using time-dependent Hartree-Fock (TDHF) method have been computed at the wavelengths used in SHG measurements.Öğe Preamble: new development on advanced materials for photonics, sensing and energy applications(SPRINGER, 2014) Sahraoui, Bouchta; Boughaleb, Yahia; Zawadzka, Anna; Karakas, Asli[Abstract not Available]Öğe 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. Mehmet4-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.Öğe 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]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, AyhanTo 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.Öğe 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. NuriN-(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.Öğe 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, AyhanA 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.Öğe 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, AyhanN,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.Öğe Synthesis, structure, linear and third-order nonlinear optical behavior of N-(3-hydroxybenzalidene)4-bromoaniline(ELSEVIER SCIENCE BV, 2008) Karakas, Asli; Uenver, Hueseyin; Elmali, AyhanN-(3-Hydroxybenzalidene)4-bromoaniline has been synthesized. Its crystal structure has been determined by X-ray diffraction analysis. To investigate 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 time-dependent Hartree-Fock (TDHF) method. The one-photon absorption (OPA) characterization has been theoretically obtained by means of configuration interaction (CI) method. The maximum OPA wavelengths are estimated in the UV region to be shorter than 450 nm, showing good optical transparency to the visible light. According to ab-initio calculation results on (hyper)polarizabilities, the synthesized molecule exhibits second hyperpolarizabilities with non-zero values, and it might have microscopic third-order NLO behavior. (C) 2007 Elsevier B.V. All rights reserved.Öğe Theoretical studies on linear and nonlinear optical characterization and optical limiting property of Pb(II), In(III) chloride, Ni(II) metallated 1,4,8,11,15,18,22,25-octaalkylphthalocyanines(WORLD SCIENTIFIC PUBL CO PTE LTD, 2007) Karakas, Asli; Elmali, AyhanTo provide an insight into the optical limiting ( OL) behavior of a series of 3 metallated 1,4,8,11,15,18,22,25-octaalkylphthalocyanines; the third-order nonlinear optical ( NLO) properties, one-photon absorption ( OPA) and two-photon absorption ( TPA) characterizations have been theoretically investigated by means of AM1, ZINDO and configuration interaction ( CI) methods. The highest values for the TPA cross-section ( delta(omega)) are exhibited by derivatives metallated with indium and lead. It is also seen that the nickel-metallated compound might be a passive optical limiter of the series, indicating the weakest delta(omega) and second hyperpolarizability (gamma). Our calculated results are in good agreement with the previous experimental observations on the examined molecules.Öğe 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, HulyaN,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.Öğe Third-order nonlinear optical properties and crystal structures of N-(2-nitrobenzalidene)-2,4-dimethylaniline and N-(3-nitrobenzalidene)2,4-dimethylaniline(VERLAG Z NATURFORSCH, 2007) Karakas, Asli; Unver, Hueseyin; Elmali, AyhanN-(2-nitrobenzalidene)-2,4-dimethylaniline (1) and N-(3-nitrobenzalidene)-2,4-dimethylaniline (2) have been synthesized and characterized by X-ray diffraction analysis. Linear optical characteristics have been evaluated theoretically using the configuration interaction (CI) method. The maximum one-photon absorption (OPA) wavelengths of the studied compounds are shorter than 450 nm, giving rise to good optical transparency in the visible and near IR regions. To provide an insight into the third-order nonlinear optical (NLO) behavior of the title molecules, both dispersion-free (static) and frequency-dependent (dynamic) linear polarizabilities (a) and second hyperpolarizabilities (gamma) at lambda = 825 - 1125 nm and 1050 - 1600 nm wavelength ranges have been computed using the time-dependent Hartree-Fock (TDHF) method. The ab initio computational results on (hyper)polarizabilities reveal that both compounds exhibit second hyperpolarizabilities with non-zero values, implying microscopic third-order NLO behavior.Öğe Third-order nonlinear optical properties and structures of (E)-N-(4-nitrobenzylidene)-2,6-dimethylaniline and (E)-N-(4-nitrobenzylidene)-2,3-dimethylaniline(PERGAMON-ELSEVIER SCIENCE LTD, 2010) Karakas, Asli; Unver, Hueseyin(E)-N-(4-Nitrobenzylidene)-2,6-dimethylaniline (1) and (E)-N-(4-nitrobenzylidene)-2,3-dimethylaniline (2) have been synthesized. The crystal structures of both compounds have been defined by X-ray diffraction analysis. The maximum one-photon absorption (OPA) wavelengths recorded by quantum mechanical computations using a configuration interaction (Cl) method are estimated in the UV region to be shorter than 450 nm, showing good optical transparency to the visible light. To provide an insight into the microscopic third-order nonlinear optical (NLO) properties of the investigated molecules, 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 have been computed using time-dependent Hartree-Fock (TDHF) method. According to the ab initio calculation results, the title molecules exhibit second hyperpolarizabilities with non-zero values, implying microscopic third-order NLO behavior. (C) 2010 Elsevier B.V. All rights reserved.Öğe Third-order nonlinear optical properties of copper(II)bis{2-[(4-iodophenyl)iminomethyl]-6-methoxy-phenolate}(VERLAG Z NATURFORSCH, 2006) Yaglioglu, Halime G.; Karakas, Asli; Unver, Hseyin; Elmali, AyhanCopper(II)bis {2-[(4-iodophenyl)iminomethyl]-6-methoxy-phenolate} has been synthesized, characterized by UV-visible spectroscopy, and its crystal structure determined by X-ray diffraction. The Cu atom is situated on a twofold axis and the geometry around the metal centre can be described as distorted square planar with a trans configuration. The absorption maxima are shorter than 450 nm, giving rise to good optical transparency in the visible and near IR. To reveal the microscopic third-order NLO properties, the static second hypetpolarizabilities have been evaluated by using the ab initio time-dependent Hartree-Fock (TDHF) method. According to the results, the title complex exhibits non-zero gamma values, implying microscopic third-order NLO behavior.