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Öğe Computational studies on linear, second and third-order nonlinear optical properties of novel styrylquinolinium dyes(ELSEVIER, 2016) Karakas, A.; Karakaya, M.; Taser, M.; Ceylan, Y.; Gozutok, A.; Arof, A. K.; El Kouari, Y.The electric dipole moments (mu), static dipole polarizabilities (alpha) and first hyperpolarizabilities (beta) of styrylquinolinium dyes, D8 and D21, have been computed by density functional theory (DFT). The one photon absorption (OPA) characterizations have been investigated using UV-vis spectroscopy and further interpreted using computational chemistry. The time-dependent Hartree-Fock (TDHF) method has been used to describe the dynamic dipole polarizabilities, dynamic second-order and also static and dynamic third-order nonlinear optical (NLO) properties. D8-D21 have rather high beta and second hyperpolarizabilities (gamma). The highest occupied molecular orbitals (HOMO), the lowest unoccupied molecular orbitals (LUMO) and the HOMO-LUMO band gaps for D8-D21 have been evaluated by DFT. (C) 2016 Elsevier B.V. All rights reserved.Öğe One-photon Absorption Characterizations, Dipole Polarizabilities and Second Hyperpolarizabilities of Chlorophyll a and Crocin(SCIENDO, 2018) Karakas, A.; Ceylan, Y.; Karakaya, M.; Taser, M.; Terlemez, B. B.; Eren, N.; El Kouari, Y.The dispersion-free dipole polarizability (alpha) computations for chlorophyll a (1) and crocin (2) have been achieved by density functional theory (DFT) at B3LYP/ 6-31G(d) level. The measured one-photon absorption (OPA) wavelengths are quite consistence with the theoretically obtained values. Ab-initio quantum chemical calculations (time-dependent Hartree-Fock (TDHF)) have been implemented to reveal the static second hyperpolarizabilities (gamma) and dynamic dipole polarizabilities of the title molecules. The examined compounds display gamma with non-zero values, introducing their third-order nonlinear optical (NLO) phenomena. The first and second frontier molecular orbitals of the investigated molecules have been also derived from DFT.Öğe Oscillator strengths for singly ionized oxygen(SPRINGER, 2009) Ates, S.; Tekeli, G.; Celik, G.; Akin, E.; Taser, M.The electric dipole oscillator strengths for multiplet and individual lines between some doublet and quartet levels have been calculated using the weakest bound electron potential model theory (WBEPMT) in singly ionized oxygen. We employed both numerical Coulomb approximation (NCA) wave functions and numerical non-relativistic Hartree-Fock (NRHF) wave functions for expectation values of radii in determination of parameters. The calculated oscillator strengths have been compared with available theoretical and experimental results. A good agreement with results in literature has been obtained. Moreover, oscillator strengths not existing in the literature for some highly excited levels have been obtained using this method.Öğe Second and third-order nonlinear optical behavior of natural pigment: chlorophyll and crocin(SPRINGER HEIDELBERG, 2017) Karakas, A.; Karakaya, M.; Taser, M.; Ceylan, Y.; Arof, A. K.; El Kouari, Y.; Sahraoui, B.To provide an insight into the microscopic second and third-order nonlinear optical (NLO) behavior of chlorophyll a and crocin, we have computed the electric dipole moments (mu), dispersion-free first hyperpolarizabilities (beta), frequency-dependent first and second (gamma) hyperpolarizabilities at 1064 nm wavelength area using time-dependent Hartree-Fock (TDHF) method. According to ab-initio calculation results, the examined compounds exhibit first and second hyperpolarizabilities with non-zero values, implying second and third-order NLO phenomena.Öğe Second-Order Hyperpolarizability and Susceptibility Calculations of a Series of Ruthenium Complexes(IEEE, 2013) Karakas, A.; Dag, T.; Taser, M.; Fillaut, J-L; Migalska-Zalas, A.; Sahraoui, B.The ab-initio quantum mechanical calculations (time-dependent Hartree-Fock (TDHF) method) of a series of ruthenium complexes have been carried out to compute electric dipole moment (mu), dispersion-free and frequency-dependent first hyperpolarizability (beta) values. The one-photon absorption (OPA) characterizations have been also theoretically investigated by means of configuration interaction (CI) method. Our calculated results on the maximum OPA wavelengths and second-order hyperpolarizabilities are in good agreement with the observed values in the literature. According to the results of the TDHF calculations, the investigated molecules exhibit non-zero beta values, and they might have microscopic second-order nonlinear optical (NLO) behaviour. We also give the computational results of the frequency-dependent second-order susceptibilities (X-(2)) for the examined compounds. The calculated results on dynamic (X-(2)). are quite consistent with the previous experimental observations.Öğe Second-order nonlinearities of anionic 3-dicyanomethylen-5,5-dimethyle-1-[2-(4-hydroxyphenyl)ethenyl)]-cyclohexene(ELSEVIER SCIENCE BV, 2016) Karakaya, M.; Karakas, A.; Taser, M.; Wolska, N.; Arof, A. K.; Sahraoui, B.Due to the connecting one pi -conjugated group with the two backside donor and acceptor groups, anionic 3-dicyanomethylen-5,5-dimethyle-1-[2-(4-hydroxyphenyl)ethenyl)]-cyclohexene (1) might possess nonlinear optical (NLO) properties. To estimate the potential for second-order NLO behaviour; the electric dipole moments and dispersion-free dipole polarizabilities and first hyperpolarizabilities have been determined by density functional theory (DFT) at B3LYP/6-31++G(d, p) level. Quantum mechanical calculations using time-dependent Hartree-Fock (TDHF) procedure have been utilized to evaluate frequency-dependent second-order nonlinearities of 1. The one-photon absorption (OPA) characterization of 1 has been theoretically obtained by means of configuration interaction (CI) with 6-31G basis set. Our theoretical results on the maximum OPA wavelength, second-order susceptibilities and corresponding microscopic NLO responses are accorded with the previous experimental observations of the investigated compound. The highest occupied molecular orbitals, the lowest unoccupied molecular orbitals and the HOMO-LUMO band gaps for 1 have been also examined by DFT/B3LYP method. (C) 2016 The Authors. Published by Elsevier Ltd.Öğe Theoretical diagnostics of second and third-order hyperpolarizabilities of several acid derivatives(DE GRUYTER POLAND SP ZOO, 2019) Karakas, A.; Ceylan, Y.; Karakaya, M.; Taser, M.; Terlemez, B. B.; Eren, N.; El Kouari, Y.The density functional theory (DFT) at B3LYP/6-31G(d) level has been utilized to achieve the electric dipole moment (mu), static dipole polarizability (alpha) and first hyperpolarizability (beta) values for ferulic acid (1) and chenodeoxycholic acid (2). The time-dependent Hartree-Fock (TDHF) technique as a powerful quantum chemical method has been implemented to reveal the dynamic alpha, beta and third-order hyperpolarizabilities (gamma) of the examined compounds. Our computational conclusions have been compared with the results of similar materials in the literature. The first and second frontier molecular orbitals (MOs) and their band gaps have also been investigated by means of DFT.Öğe Z-Scan Determination and Ab-Initio Computations on Third-Order Optical Nonlinearities of a Styrylquinolinium Dye(IEEE, 2014) Karakas, A.; Sofiani, Z.; Ceylan, Y.; Taser, M.; Bakalska, R.; Todorova, M.; Sahraoui, B.In order to elucidate the third-order nonlinear optical (NLO) phenomena of the styrylquinolinium dye (1), the nonlinear absorption parameter (beta) and third-order susceptibility (chi((3))) have been measured using the Z-scan measurements. The one-photon absorption (OPA) and two-photon absorption (TPA) characterizations have been determined by configuration interaction (CI) and time-dependent Hartree-Fock (TDHF) methods, respectively. The averaged (isotropic) second hyperpolarizability () allows the determination of the third-order optical response. The ab-initio calculation on with non-zero value reveals that the title dye has relatively good third-order NLO properties. The calculated results of 1 on OPA wavelength, TPA cross-section (delta(omega)) and third-order susceptibility are in reasonable agreement with its experimental data.
