Yazar "Kurekci, Mehmet" seçeneğine göre listele

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    Öğe
    Experimental and computational study on molecular structure and vibrational analysis of an antihyperglycemic biomolecule: Gliclazide
    (Pergamon-Elsevier Science Ltd, 2015) Karakaya, Mustafa; Kurekci, Mehmet; Eskiyurt, Buse; Sert, Yusuf; Cirak, Cagri
    In present study, the experimental and theoretical harmonic vibrational frequencies of gliclazide molecule have been investigated. The experimental FT-IR (400-4000 cm(-1)) and Laser-Raman spectra (100-4000 cm(-1)) of the molecule in the solid phase were recorded. Theoretical vibrational frequencies and geometric parameters (bond lengths and bond angles) have been calculated using ab initio Hartree Fock (HF), density functional theory (B3LYP hybrid function) methods with 6-311++G(d,p) and 6-31G(d,p) basis sets by Gaussian 09W program. The assignments of the vibrational frequencies were performed by potential energy distribution (PED) analysis by using VEDA 4 program. Theoretical optimized geometric parameters and vibrational frequencies have been compared with the corresponding experimental data, and they have been shown to be in a good agreement with each other. Also, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies have been found. (C) 2014 Elsevier B.V. All rights reserved.
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    Öğe
    Structural optimization and vibrational analysis of an antidiabetic drug: tolbutamide
    (Taylor & Francis Ltd, 2015) Sert, Yusuf; Karakaya, Mustafa; Cirak, Cagri; Eskiyurt, Buse; Kurekci, Mehmet
    The purpose of this study is to investigate the vibrational spectrum of tolbutamide by ab initio techniques in combination with experimental studies. The Fourier transform infrared spectra (400-4000 cm(-1)) and Laser-Raman spectra (100-4000 cm(-1)) of tolbutamide have been obtained in the solid phase. Assignments have been found by the combination of the vibrational frequencies and the contribution of the potential energy distributions. Assignments have been compared with the theoretical and experimental results of similar structures as reported in the literature. Structural parameters such as bond lengths and angles, frequencies and infrared intensities and Raman activities of tolbutamide have been computed by density functional theory and Hartree-Fock methods using 6-311G++(d,p) and 6-31G(d) basis sets. The computed vibrational frequencies and optimized structural parameters are consistent with the corresponding experimental results. In addition, the images of tolbutamide frontier molecular orbitals (highest occupied and lowest unoccupied) and its energy gaps have been interpreted with the assistance of quantum chemical calculations.
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    Öğe
    Theoretical and experimental investigations on vibrational and structural properties of tolazamide
    (Elsevier, 2015) Karakaya, Mustafa; Sert, Yusuf; Kurekci, Mehmet; Eskiyurt, Buse; Cirak, Cagri
    In this paper, vibrational spectra of tolazamide have been investigated by ab initio techniques in combination with experimental studies. Data on the FT-IR spectra (400-4000 cm(-1)) and Laser-Raman spectra (100-4000 cm(-1)) of tolazamide have been obtained in the solid phase. Assignments corresponding to the vibrational frequencies have been found and interpreted by the contribution of the potential energy distributions. The theoretical results are compared X-ray experimental data for this. Structural parameters such as bond lengths and angles, frequencies and intensities regarding Raman and IR spectra of the compound have been computed by density functional theory and Hartree-Fock methods with 6-311G++(d,p) and 6-31G(d) basis sets. They have been observed that the computed vibrational frequencies and optimized structural parameters are consistent with the corresponding experimental results. In addition, the images of frontier molecular orbitals (highest occupied and lowest unoccupied) have been presented and interpreted. (C) 2015 Elsevier B.V. All rights reserved.