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    Crystal structure, Hirshfeld surface analysis and DFT studies of (E)-4-methyl-2-{[(2-methyl-3-nitrophenyl)imino]methyl}phenol
    (INT UNION CRYSTALLOGRAPHY, 2020) Cinar, Emine Berrin; Faizi, Md Serajul Haque; Yagci, Nermin Kahveci; Dogan, Onur Erman; Aydin, Alev Sema; Agar, Erbil; Dege, Necmi
    The title compound, C15H14N2O3, was prepared by condensation of 2-hydroxy-5-methyl-benzaldehyde and 2-methyl-3-nitro-phenylamine in ethanol. The configuration of the C=N bond is E. An intramolecular O-H center dot center dot center dot N hydrogen bond is present, forming an S(6) ring motif and inducing the phenol ring and the Schiff base to be nearly coplanar [C- C-N-C torsion angle of 178.53 (13)degrees]. In the crystal, molecules are linked by C-H center dot center dot center dot O interactions, forming chains along the b-axis direction. The Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H center dot center dot center dot H (37.2%), C center dot center dot center dot H (30.7%) and O center dot center dot center dot H (24.9%) interactions. The gas phase density functional theory (DFT) optimized structure at the B3LYP/ 6-311 G(d,p) level is compared to the experimentally determined molecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.
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    Crystal structure, Hirshfeld surface analysis and DFT studies of (E)-4-methyl-2-{[(4-methylphenyl)-imino]methyl}phenol
    (INT UNION CRYSTALLOGRAPHY, 2020) Yagci, Nermin Kahveci; Faizi, Md Serajul Haque; Aydin, Alev Sema; Dege, Necmi; Dogan, Onur Erman; Agar, Erbil; Mashrai, Ashraf
    In the title compound, C15H15NO, the configuration of the C=N bond of the Schiff base is E, and an intramolecular O-H center dot center dot center dot N hydrogen bond is observed, forming an intramolecular S(6) ring motif. The phenol ring is inclined by 45.73 (2)degrees from the plane of the aniline ring. In the crystal, molecules are linked along the b axis by O-H center dot center dot center dot N and C-H center dot center dot center dot O hydrogen bonds, forming polymeric chains. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the packing arrangement are from H center dot center dot center dot H (56.9%) and H center dot center dot center dot C/C center dot center dot center dot H (31.2%) interactions. The density functional theory (DFT) optimized structure at the B3LYP/ 6-311 G(d,p) level is compared with the experimentally determined molecular structure, and the HOMO-LUMO energy gap is provided. The crystal studied was refined as an inversion twin.
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    Magnetic properties of the David star in the 2D-Kagome lattice
    (Taylor & Francis Ltd, 2021) Yagci, Nermin Kahveci
    We investigate the magnetisation and internal energy of the David star in the Kagome lattice by the effective field theory developed by Kaneyoshi. First-order, Second-order and successive phase transitions are observed for different spin-down orientations. Spin-down orientation of identical atoms causes a second-order phase transition, spin-down orientation of different atoms causes a first-order and successive phase transitions. Minimum internal energy is obtained as U (David star )=( )-5 for all spin-up orientations, whereas it increases (U (David star )> -5) for at least one spin-down orientation. For spin-down orientation of A up arrow-A down arrow, internal energy becomes zero at a certain temperature and we call this temperature 'zero internal energy temperature (Tzie)'. At T < Tzie( )=( )1.99, internal energy is positive, whereas it is negative for other spin states. Therefore, spin-induced minimum internal energy broken is observed except for all spin-up (A up arrow, B up arrow and C up arrow) cases.
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    Magnetic properties of the Martensitic transformations with twinned and detwinned
    (Elsevier Science Bv, 2019) Sarli, Numan; Yildiz, Gokcen Dikici; Yildiz, Yasin Gokturk; Yagci, Nermin Kahveci
    The effects of the Austenite (A), twinned Martensite (TM) and detwinned Martensite (DTM) structural transformations on the ferromagnetic properties are investegated by means of the effective field theory developed by Kaneyoshi. We find that the critical Curie temperature of the A, TM and DTM is obtained as T-c(A) < T-c(DTM)< T-c(TM) for H = 0. Thermal magnetization loops are obtained for H not equal 0. The area of the thermal magnetization loops of the A-TM is wider than those of the A-DTM. Paramagnetic Austenite has a phase transition from paramagnetic (PM) phase to ferromagnetic (FM) phase at T-c(TM) and T-c(DTM). The temperature of the As (Austenite start), TMf (twinned Martensite finish) and DTM f (detwinned Martensite finish) increase as the external magnetic field (H) increases. The magnetizations of the A, TM and DTM are the same at low temperature (T < A(s)). The coercive field points are obtained as H-c(A) < H-c(DTM)< H-c(TM). The shearing angle plays very important role in the structural transformations and their ferromagnetic properties, especially in TM.
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    Perpendicular Magnetic Anisotropy Revealed by c/a Ratio of Mn2NiB Heusler Alloy
    (Springer, 2021) Yagci, Nermin Kahveci
    c/a ratio effects on the magnetic properties of the Mn2NiB Heusler alloy are investigated by using effective field theory developed by Kaneyoshi. It is found that the Curie temperature and coercive fields of the Mn2NiB are obtained as Tc-IT > Tc(C) > Tc-NT = 0.92 and Hc(IT) > Hc(C) > Hc(NT) = 0.00 for c/a < 1 (inverse tetragonal), c/a = 1 (cubic), and c/a > 1 (normal tetragonal), respectively. These magnetic differences show that the c/a ratio causes a perpendicular magnetic anisotropy (PMA). Therefore, we suggest that PMA strongly depends on the c/a ratio, atomic distance, and exchange interactions between two atoms (Mn-Ni and Mn-B) on the ca surfaces of the Mn2NiB.
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    Synthesis, crystal structure, antibacterial activity and theoretical studies on a novel Zn(II) complex based on 2,4,6-tris(2-pyridyl)-1,3,5-triazine ligand
    (Elsevier, 2021) Guven, Gamze Bakir; Cinarli, Murat; Sas, Emine Babur; Idil, Onder; Yagci, Nermin Kahveci
    It is known that 2,4,6-tri(2-pyridyl)-1,3,5-triazine (tptz) also belongs to noticeable building blocks in both organic and inorganic supramolecular chemistry. We have prepared new Zn(II) complex of 2,4,6-tri(2-pyridyl)-1,3,5-triazine. The new metal complex was characterized by elemental analysis, IR spectra, UV spectra measurements. The molecular structure of [Zn(tptz)(Cl)(2)] was investigated by X-Ray single crystal technique. From all data, the stoichiometry of the complex was found to be 1:1 (metal/ligand). The all data indicated that the tptz exhibits major coordination site behavior. Potential energy surface (PES) was calculated using the DFT / B3LYP / 6-311 G (d, p) method to determine the lowest energy state of the molecular structure. Geometric structure parameters and vibration wavenumbers calculated according to the lowest energy state were compared with experimental data. The electronic properties such as frontier molecular orbital analysis and Uv-Vis spectrum obtained at acetonitrile solvent and gas phase were also studied.). The [Zn(tptz)(Cl)(2)] complex was screened for antibacterial activity against Gram-positive, Gram-negative and yeast by using minimal inhibitory concentration method (MIC). [Zn(tptz)(Cl)(2)] has been found to show significant antimicrobial effects on gram (-), gram (+) and eukaryotic yeast. The DNA binding interactions was also determined experimentally by spectrophotometric and electrochemical methods. (C) 2021 Published by Elsevier B.V.
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    Synthesis, crystal structure, DFT studies, Hirshfeld surface analysis and drug delivery performance of bis(2-chloro-4,6-diaminopyrimidine)copper(II)-dichloride
    (Elsevier, 2021) Yagci, Nermin Kahveci; Kansiz, Sevgi; ozcandan, Eda
    The new single crystal, bis(2-chloro-4,6-diaminopyrimidine)-copper(II)-dichloride [CDPCD] compound was synthesized. The crystal structure of the compound was solved by the single crystal X-ray diffraction method. CDPCD has a = 6.3334(9) angstrom, b = 6.9914 (10) angstrom, c = 8.9901(12) angstrom, alpha = 78.127(11) degrees, beta = 86.853(11) degrees, gamma = 67.307(10)degrees and Z = 1 parameters and is crystallized in the space group P-1 in the triclinic crystal system. Complete vibration assignments of CDPCD in gas phase and experimental frequencies are reported together with the scaled force constants. The optimized geometric parameters and frequency values were theoretically calculated using DFT/B3LYP method with LANL2DZ basis set. The XRD single crystal measurement parameters are good agreed with the optimized parameters. Molecular orbital surfaces and molecular electrostatic potential properties were measured at B3LYP/LANL2DZ level. Hirshfeld surface and fingerprint drawings were obtained to explain the intermolecular interactions of the crystal structure. The most important contributions for the crystal packing are from Cl center dot center dot center dot H/H center dot center dot center dot Cl (38.7%), H center dot center dot center dot H (17.9%) and N center dot center dot center dot H/H center dot center dot center dot N (14.8%) interactions. In addition, the molecule was tested by MTT test to determine the apoptosis and necrosis by cytotoxicity and double staining method. For the MTT test [MTT: (3,4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide], the tetrazolium salt was used. In different percentages of the compound, apoptotic necrotic index ratios of L929 fibroblasts and MCF-7 cells decreased. Bilateral staining method was used to evaluate the cells that had undergone apoptosis and necrosis of FITC (480-520nm wavelength). Apoptotic and necrotic index results of L929 fibroblasts and MCF-7 cells decreased as the amount of concentration decreased. (C) 2021 Elsevier B.V. All rights reserved.