Yazar "Meral, Seher" seçeneğine göre listele

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    Comparative structural, spectroscopic and nonlinear optical analysis of a Schiff base compound with experimental and theoretical methods (HF, B3LYP and WB97X-D)
    (Elsevier Gmbh, 2021) Evecen, Meryem; Tanak, Hasan; Agar, Aysen Alaman; Meral, Seher; Ozdemir, Namik
    A novel Schiff base compound (E)-N-((2-iodophenyl)-1-(5-nitrothiophen-2-yl)methanimine has been synthesized. The structural characterization of Schiff base compound are confirmed by single crystal X-ray, FT-IR, and UV-vis techniques. The theoretical calculations were obtained by aid of the HF, DFT/B3LYP and WB97X-D methods with the LANL2DZ basis set. The electronic properties and vibrational frequencies in the ground state were investigated same levels of theory. The UV-vis experimental results are compared to the calculated TD-DFT and TD-HF results. The NLO properties have been predicted using same calculations and compared with urea molecule. Results indicate that compound is a good candidate as NLO material.
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    Crystal structure and Hirshfeld surface analysis of 2,2′{(1 E,1′E)-[ethane-1,2-diyibis(azanylyunene)]-bis(methanylylidene)}bis[4-(traluorometnoxy)-phenol]copper(II) hydroquinone hermsoiyate
    (Int Union Crystallography, 2019) Kansiz, Sevgi; Meral, Seher; Dege, Necmi; Agar, Aysen Alaman; Fritsky, Igor O.
    In the title complex, [Cu(C18H12F6N2O4)]center dot 0.5C(6)H(6)O(2), the Cu-II ion has a square-planar coordination geometry, being ligated by two N and two O atoms of the tetradentate open-chain Schiff base ligand 6,6'-{(1E,1'E)-[ethane-1,2-diyl-bis (azanylylidene)] bis (methanylylidene)}bis [2-(trifluoromethoxy) phenol].The crystal packing is stabilized by intramolecular O-H center dot center dot center dot O and intermolecular C-H center dot center dot center dot F, C-H center dot center dot center dot O and C-H center dot center dot center dot pi hydrogen bonds. In addition, weak pi-pi interactions form a three-dimensional structure. Hirshfeld surface analysis and two-dimensional fingerprint plots were performed and created to analyze the intermolecular interactions present in the crystal, indicating that the most important contributions for the crystal packing are from F center dot center dot center dot H/H center dot center dot center dot F (25.7%), H center dot center dot center dot H (23.5%) and C center dot center dot center dot H/H center dot center dot center dot C (12.6%) interactions.
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    Crystal Structure, Spectroscopic and DFT Computational Studies of N-(4-Fluorophenyl)-1-(5-Nitrothiophen-2-yl)methanimine
    (Pleiades Publishing Inc, 2020) Tanak, Hasan; Karatas, Sadiye; Meral, Seher; Agar, Aysen Alaman
    A novel Schiff base compound was synthesized and characterized by IR spectroscopy and X-ray diffraction method. The compound crystallizes in monoclinic space group P21/c with Z = 4 in the unit cell. The ring systems are perfectly planar but the whole molecule is not planar. The dihedral angle between the thiophene and phenyl rings is 38.7(3)degrees. In the crystal, intermolecular C-H center dot center dot center dot O interactions link the molecules into a C(7) chain along the [20 $$(1) over bar] direction. The crystal packing is also stabilized by N-O center dot center dot center dot pi interaction. The molecular structure and vibrational frequencies of the title compound were calculated using the DFT/B3LYP method with the 6-311++G(d,p) basis set. The calculated results show that the optimized geometry can well reproduce the crystal structure, and the theoretical vibrational frequencies show good agreement with experimental results.
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    Determination of antimicrobial and antimutagenic properties of some Schiff bases
    (Acad Brasileira De Ciencias, 2021) Ogutcu, Hatice; Meral, Seher; Ceker, Selcuk; Agar, Aysen Alaman; Agar, Guleray
    In this study, we aimed to investigate for the first time antimicrobial and antimutagenic activities new two Schiff bases, obtained from a primary amine (p-toluidine, o-toluidine) and an aldehyde (Helicin). Synthesized compounds characterized with elemental analysis, fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometry. H-1-C-13 nuclear magnetic resonance spectroscopy. Antimutagenic activity was evaluated by micronuclei assay. Antimicrobial activity of Schiff bases have been demonstrated against pathogenic four Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermis, Micrococcus luteus, Bacillus cereus) and four Gram-negative bacteria (Pseudumonas aeroginosa, Salmonella typhi H, Brucella abortus, Escherichia coli) and two yeasts (Candida albicans and Saccharomyces cerevisiae). The results showed that both Schiff bases have antimutagenic activity. Especially, high concentration (20 mu M) of (E)-2-(hydroxymethyl)-6-(2-((p-tolylimino)methyl)phenoxy)tetrahydro-2H-pyran-3,4,5-triol (Compound I) and (E)-2-(hydroxymethyl)-6-(2-((o-tolylimino)methyl)phenoxy)tetrahydro-2H-pyran-3,4,5-triol (Compound II) have strong antimutagenic activity against aflatoxin B-1. On the other hand, both of studied compounds were found effective against pathogenic bacteria and yeasts. Compound I exhibited more activity against P. aeroginosa, S aureus, S.typhi H and C. albicans comparable to Compound II and standard antibiotics. Additionally, Compound II showed better inhibitory activity than Compound I against Candida albicans and Br. Abortus. Therefore, these compounds can be used in phytotherapeutic due to theirs antimutagenic and antimicrobial activities.
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    Experimental and theoretical comparison of the vibrational and NMR spectra of novel 6-6'-(1E-1'E)-(Propane-1,3Diylbis (Azanylyidene)) Bis (Phenylmethylylidene)) Bis (3-Octyloxy) Phenol), NBO and molecular docking studies
    (Elsevier, 2024) Gumus, Sedat; Guner, Huriye; Meral, Seher; Agar, Aysen Alaman
    The characterization study of the synthesized novel compound 6-6'-(1E-1'E)-(Propane-1,3Diylbis(Azanylyidene))Bis(Phenylmethylylidene))Bis(3-Octyloxy)Phenol) (C45H58N2O4) was done by FT-IR, Raman and NMR spectra. Vibrational analysis was realized with normal coordinate treatment, and vibrational modes were assigned in the mid-IR region. The 13C and 1H -NMR spectra of the title compound were measured in DMSO and chloroform, and the corresponding chemical shifts were calculated in the different basis sets (6-31++G(d,p), 6311G(2d,p), 6-311++G(2d,p), TZVPP) of DFT-B3LYP with continuum models. The vibrational and NMR spectroscopies show that the existence of the intramolecular resonance-assisted hydrogen bonds(O-H...N) results in the redshift of OH vibrational modes and its high proton chemical shifts (ca. 16 ppm), as confirmed by X-ray crystal structure and NRT studies.13C NMR chemical shifts of the Schiff base bond are determined as ca. 174 ppm. The calculations indicate that both the intramolecular hydrogen bond strength and the OH-proton chemical shift increase with increasing solvent polarity. The molecular docking studies reveal that the title ligand has the potency of inhibition against the VIM-2 and NDM-1 active sites of metallo-/q-lactamase receptor.
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    Exploring crystal structure, Hirshfeld surface and quantum mechanical attributes of symmetric thiophene Schiff base
    (Springer, 2023) Meral, Seher; Agar, Aysen Alaman; Cinar, Emine Berrin; Dege, Necmi; Kanmazalp, Sibel Demir; Vidya, V. G.; Kumar, V. G. Viju
    A novel compound (1E,1 ' E)-N,N '-(ethane-1,2-diyl)bis(1-(5-nitrothiophen-2-yl)methanimine) [EDNM] was synthesized from thiophene derivative in view to get multidentate ligand with potential biological activity. EDNM is characterized by FT-IR, 1H and 13C NMR and UV-Vis spectroscopic techniques and confirmed by SCXRD. EDNM crystallizes in the monoclinic system with P21/c space group with Z value 4 and unit cell parameters a = 5.6540(3) angstrom, b = 17.9249(8) angstrom and c = 7.5077(5) angstrom. DFT was employed for theoretical evaluations using B3LYP with the basis set 6-311 + + G (d,p). Geometry optimization, vibrational analysis, NMR, electronic absorption, MEP, FMO, Mulliken charges and NBO analysis were performed, thereby establishing the nature of reactive sites, band energy gap and atomic charges of EDNM. Theoretical values matched well with the experimental findings. NBO analysis revealed the donor acceptor interactions in molecule. Analysis of global reactivity descriptors along with Fukui indices outlines the elaborate scheme of reactive sites of the molecule, and Hirshfeld surface investigation revealed the intermolecular interactions in crystal packing.
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    Molecular structure, spectroscopic and DFT studies of 2-(4 ethoxyphenyl) isoindoline-1,3-dione
    (Natl Inst Science Communication-Niscair, 2021) Evecen, Meryem; Tanak, Hasan; Duru, Gulcan; Meral, Seher; Agar, Aysen Alaman
    2-(4-Ethoxyphenyl)isoindoline-1,3-dione molecule has been characterized by experimental FT-IR and UV-visible spectroscopic methods. Density factional theory calculations of the molecular structure and vibrational spectra have been performed using the B3LYP/6-311++G(d,p) level of theory for the 2-(4-ethoxyphenyl)ignndoline-1,3-dione. The theoretical results arc compared with the experimental observations. Using the TD-DFT methodology, the electronic absorption spectra of the investigated molecule have been calculated. The enthalpy, entropy and heat capacity properties based on the vibrational calculations are calculated at different temperatures. Besides, the frontier orbitals, atomic charges, reactivity descriptors, molecular electrostatic potential, interaction energies and nonlinear optical properties are predicted by the density functional theory calculations.
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    Sentezlenen Yeni Ni (II) Komplekslerinin Spektroskopik ve antifungal özelliklerinin İncelenmesi
    (2020) Karakurt, Tuncay; Meral, Seher; Ağar, Ayşen Alaman; Onaran, Abdurrahman
    Bu çalışmada, 6,6'-((1E,1'E)-(propan-1,3 diilbis(azanildien))bis(fenillmetanildien))bis(3-(oktiloks)fenol) (HL1)ve 6,6’-((1E,1’E)-(etan-1,2-diilbis(azanildien))bis(fenillmetanildien))bis(3-(oktiloks)fenol) (HL2) ligandları ile Ni metal atomunun iki farklı kompleksi (HL1Ni ve HL2Ni ) sentezlendi ve NMR, FT–IR ve UV–Vis spektroskopik yöntemleri ile karakterize edildi. İki kompleks yapının in vitro koşullar altında Rhizoctonia solanive Fusarim oxysporum f.sp radicis–lycopersici (FORL) bitki patojenlerine karşı antifungal aktivite çalışmaları yapıldı. Etkinliği belirlenen bileşiklerin doz miktarına göre test edilen patojenlere karşı orta ve yüksek düzeyde aktivite sergilediği belirlendi. Ayrıca Kompleks yapıların moleküller arası etkileşimlerin daha iyi anlaşılabilmesi amacıyla da bileşiklerin HOMO–LUMO orbitalleri teoriksel olarak elde edildi. Son olarak da moleküler doking çalışması ile reseptör–kompleks etkileşimleri simüle edildi. Bu hesaplama sonucunda komplekslere ait afinitedeğerleri (Doking skoru) sırasıyla -6.9 ve -6.4 kcal/mol olarak hesaplandı. Kompleks yapıların doking skorları ile HOMO orbital enerjilerinin birbirleriyle ilişki olduğu gözlendi
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    Synthesis and characterization of tetradentate benzophenone derivative Schiff base and properties in different lyotropic media
    (Taylor & Francis Ltd, 2024) Suhta, Abdurrahman; Meral, Seher; Agar, Aysen Alaman; Sutay, Berkay; Lopez, Ezequiel Vazquez M.; Coruh, Ufuk
    A new Schiff base ligand of 6,6 & PRIME;-(1Z,1 & PRIME;Z)-(butane-1,4-diylbis(azanylyidene))bis (phenylmethanylylidene))bis(3-octyloxy) phenol) was synthesized and characterized using XRD and different spectroscopic analyses (FTIR, H-1 NMR, C-13 NMR, and UV-Vis.) DFT/B3LYP/6-31G(d,p) level of theory was applied successfully to the present compound. Theoretically calculated parameters of the synthesized compound were compared with the experimentally obtained results. The optimized structure has been investigated using the same level of theory for various studies, including frontier molecular orbital analysis, molecular electrostatic potential, chemical reactivity indexes, natural bond orbital analysis, electrostatic potential, and the electrophilicity-based charge transfer with DNA bases.
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    Synthesis, Molecular Structure and Spectroscopic Studies of 6,6'-(1E,1'E)-(Ethane-1,2-Diylbis(azan-1-yl-1-ylidene))bis(Phenylmethan-1-yl-1-ylidene)bis(3-(Octyloxy)phenol)
    (Pleiades Publishing Inc, 2020) Tanak, Hasan; Meral, Seher; Agar, Aysen Alaman
    6,6'-(1E,1'E)-(ethane-1,2-diylbis(azan-1-yl-1-ylidene))bis(phenylmethan-1-yl-1-ylidene)bis(3-(octyloxy)phenol) has been synthesized and characterized by FTIR, H-1, C-13 NMR and single-crystal X-ray determination. The compound crystallizes in monoclinic space group C2/c with Z = 4 in the unit cell. The asymmetric unit of the compound contains one half-organic molecule. The molecule is located about a two-fold rotation axis which bisects the central C14-C14(i) bond. The dihedral angle between the phenyl rings is 68.46(11)degrees. In the crystal, intramolecular O-H...N hydrogen bonds generates a six-membered ring, producing an S(6) ring motif. The crystal packing is also stabilized by C-H...pi interactions.
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    Synthesis, structural studies, Hirshfeld surface analysis, and molecular docking studies of a thiophene-based Schiff base compound
    (Elsevier, 2022) Kansiz, Sevgi; Azam, Mohammad; Basili, Taskin; Meral, Seher; Aktas, Feyzi Alkim; Yesilbag, Semanur; Min, Kim
    A novel nitrothiophene derivative, (( Z )- N -(4-nitrophenyl)-1-(5-nitrothiophen-2-yl)ethan-1-imine, NNPEI, was synthesized by a condensation reaction and characterized by FT-IR, UV-Vis., 1 H-NMR and 13 C-NMR spectroscopy, and single-crystal X-ray crystallography. The structure was further confirmed by theoretical studies using the DFT/B3LYP method with LanL2Z basis set. The experimental results agree well with the findings of theoretical studies. The chemical reactivity and kinetic stability of molecular compounds are determined using the molecular frontier orbitals, HOMO and LUMO. Hirshfeld surface analysis was used to measure different interactions, revealing that the main contributions to the crystal packing come from the interactions O ...H/H ...O (42%), C ...H/H ...C (9.5%), H ...H (8.9%), S ...H/H ...S (7.9%) and N ...H/H ...N (6.3%). Furthermore, molecular docking was used to investigate the binding interactions between MCL1 and NNPEI to choose possible conformation.