1,720,999 research outputs found
Synthesis, spectroscopic characterization, DFT computations, nonlinear optical profile and molecular docking study of a novel chalcone derivative
No full textGokce, Halil/0000-0003-2258-859XWOS: 000501486700111A novel chalcone derivative, (E)-1-(3-hydroxyphenyl)-3-(2,4,6-trimethoxyphenyl)prop-2-en-1-one (Tx), was synthesized and its spectroscopic characterization was done by using the experimental FT-IR, Laser-Raman, UV-Vis. and NMR spectroscopic techniques. To support experimental spectroscopic data, computational analyses were performed with DFT/B3LYP method at the 6-311++(d,p) basis set. The assignments of fundamental vibrational modes were defined in terms of PED% by using VEDA4xx software. HOMO, LUMO and UV-Vis. Spectral analyses were used for determination of molecular electronic transitions. By considering the computed HOMO and LUMO energy values, some global reactivity descriptors were theoretically investigated. MEP surface mapping was used to determine the nucleophilic and electrophilic reactive sites within the compound Tx. Thermodynamic features of the compound were theoretically studied within gas phase. The static polarizabilities and first order hyperpolarizabilities were used to investigate non-linear optical (NLO) profile of the compound. The protein-ligand interactions for the compound Tx docked into a breast cancer resistance protein ATP-binding cassette subfamily G member 2 (PDB ID: 6FFC) were investigated with the molecular docking analysis. (C) 2019 Elsevier B.V. All rights reserved
Crystal structure, Hirshfeld surface, spectroscopic analyses, electronic properties, NLO profile and thermochemical study of an antispasmodic agent trimebutine
No full textGokce, Halil/0000-0003-2258-859XWOS: 000492858500111Absolute molecular geometry of trimebutine was determined with single crystal X-Ray diffraction (SCXRD). The C-H center dot center dot center dot O and C-H center dot center dot center dot pi interactions within crystal packing were supported by Hirshfeld surface analysis. Spectral properties of trimebutine were investigated by using analysis techniques such as FT-IR, micro-Raman, NMR chemical shift and UV-Vis. spectroscopies. In order to investigate vibrational profile of the important functional groups within the compound, the detailed assignments of vibrational wavenumbers were performed by using potential energy distribution. Theoretical investigations on structural, spectroscopic, electronic, non-linear optical and thermochemical features were carried out with the DET/B3LYP method at the 6-311++G(d,p) basis set. The C-13 and H-1 NMR chemical shifts of each atom within the compound were studied both experimentally and theoretically. The UV-Vis. spectroscopic analysis of trimebutine was used to evaluate intra-molecular electronic transitions. The HOMOs and LUMOs analyses were done to determine the nature and origin of the pi ->pi* and n ->pi* electronic transitions. Additionally, the global reactivity descriptors were defined depending upon energy values of HOMO and LUMO. The pi ->pi* and n ->pi* hyperconjugative interactions between donor and acceptor groups were investigated by NBO analysis. According to the computed alpha(total), Delta alpha and beta(0) values in the static state of trimebutine single crystal, it exhibits an excellent non-linear optical material property. Thermochemical features were calculated and studied in the gas phase of the compound. (C) 2019 Elsevier B.V. All rights reserved
Molecular docking, Hirshfeld surface, structural, spectroscopic, electronic, NLO and thermodynamic analyses on novel hybrid compounds containing pyrazole and coumarin cores
No full textGumus, Mehmet/0000-0001-9262-7940; Gumus, Mehmet/0000-0003-3643-5703; KOCA, IRFAN/0000-0001-7873-159X; Gokce, Halil/0000-0003-2258-859XWOS: 000442193700094The target compound 3-(3-(4-chlorobenzoyl)-1-phenyl-1H-pyrazole-5-carbonyl)-7-methoxy-2H-chromen-2-one was characterized by FT-IR, Laser-Raman, NMR chemical shift, UV-Vis. and single-crystal X-Ray diffraction spectroscopic techniques. The molecular geometric structure, Hirshfeld surface, HOMOLUMO, molecular electrostatic potential (MEP), non-linear optical, atomic charges, molecular docking and thermodynamic analyses were theoretically investigated to support the obtained data with experimental studies. The theoretical researches and evaluations were performed by DFT/B3LYP functional at the 6-311++G(d,p) basis set in the ground state of the compound. The assignments of computed harmonic vibrational wavenumbers were determined in terms of potential energy distribution (PED) analysis. Hirshfeld surface analysis was studied to examine intermolecular interactions in crystal packing of the compound. The experimental results on molecular geometry and spectral results were showed that the correlation between experimental and theoretical data is in good agreement. Additionally, for molecular docking study, macromolecule-ligand interactions between 3-(3-(4-chlorobenzoyl)-1-phenyl-1H-pyrazole-5-carbonyl)-7-methoxy-2H-chromen-2-one and interleukin-6 (IL-6) (PDB ID: 4NI9) were investigated by using AutoDock Vina program. All results related to title compound were evaluated in detail. (C) 2018 Elsevier B.V. All rights reserved.Science and Technology Practice & Research Centre of Bozok University [6602c-SMYO/17-126]The authors would like to thank Science and Technology Practice & Research Centre of Bozok University for financial support (Project No: 6602c-SMYO/17-126). The authors gratefully acknowledge the Medicinal Plants and Medicine Research Centre of Anadolu University, Eskisehir, Turkey, for the use of X-ray Diffractometer. The authors thanks to Dr. Hatice An (Bozok University) for the use of Renishawlnvia Raman microscope spectrophotometer
Structural, spectroscopic, electronic, nonlinear optical and thermodynamic properties of a synthesized Schiff base compound: A combined experimental and theoretical approach
No full textGunes, Serap/0000-0002-3358-0713; , Nuri/0000-0001-8742-0160; Gokce, Halil/0000-0003-2258-859X; Kazici, Mehmet/0000-0001-9048-7788WOS: 000397375800030A Schiff base compound, 2-[(1H-benzimidazol-2-ylimino)methy1]-4-bromophenol (BISB), was synthesized and its spectroscopic characterization was performed using experimental methods such as FT-IR, Raman, proton and carbon -13 NMR chemical shifts and UV Vis. spectroscopies. Density functional theory (DFT/B3LYP/6-311G(d,p)) computations were used to investigate the optimized molecular geometry, conformational forms, harmonic vibrational wavenumbers, NMR chemical shifts, UV Vis. spectroscopic parameters, natural bond orbital (NBO) analysis, HOMO-LUMO energies, nonlinear optical (NLO) properties, molecular electrostatic potential (MEP) map, atomic charges and thermodynamic properties of the BISB molecule. The assignments of vibrational modes were performed by means of potential energy distribution (PED) using VEDA4 program, The NBO analysis was used to investigate intramolecular hyrogen bonding (O-H center dot center dot center dot N), bond species, hyperconjugation interactions and intramolecular charge transfers (ICTs). Considering the computed HOMO and LUMO energies, the quantum molecular descriptors such as ionization potential (I), electron affinity (A), chemical hardness (eta), chemical softness (zeta), electronegativity (chi), chemical potential (mu) and electrophilicity index (omega) parameters were investigated for the BISB molecule. DFT computations were also performed to determine the dipole moment (mu) the mean polarizability (alpha), the anisotropy of the polarizability (Delta alpha) and the first hyperpolarizability (beta(0)) values. The recorded experimental spectroscopic results are in a good harmony with the computed data. (C) 2017 Elsevier B.V. All rights reserved
Structural, Spectroscopic, Electronic and Molecular Docking Studies on (11R,12 S)-16-Aminotetracyclo[6.6.2.0(2,7).0(9,14)]hexadeca-2(7),3,5,9(14),10,12-hexaen-15-ol
No full textAlanazi, Mohammed/0000-0002-0483-8113; Gokce, Halil/0000-0003-2258-859X; , Nuri/0000-0001-8742-0160; Al-agamy, Mohamed/0000-0001-9868-0355WOS: 000456717300009Molecular structure analysis, vibrational and electronic spectroscopic studies and thermochemical features of (11R,12 S)-16-aminotetracyclo[6.6.2.0(2,7).0(9,14)]hexadeca-2(7),3,5,9(14),10,12-hexaen-15-ol were investigated via both theoretical and experimental techniques. Experimental investigations were made by using FT-IR, Raman, H-1 and C-13 NMR and UV-Vis. spectroscopies. To support experimental evidences, molecular electronic structure computations were obtained with the DFT/B3LYP method at the 6-311G++(3d,3p) basis set. 2D and 3D Hirshfeld surfaces studies were performed to understand non-bonding intermolecular interactions in solid phase crystal packing of the compound. MEP surface analysis was performed to investigate nucleophilic and electrophilic reactive sites of the compound. The highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMO) analyses were theoretically used for determination of electronic transitions corresponding to UV-Vis. electronic absorption wavelengths. Enzyme-ligand interactions between the compound with BACE1 (Beta-Secretase1) inhibitor were determined via molecular docking study.Deanship of Scientific Research at King Saud UniversityDeanship of Scientific Research at King Saud University [RGP-163]The authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding the work through the research group project No. RGP-163
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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