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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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    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) Güven, Gamze Bakır; Çınarlı, Murat; Sas, Emine Babur; İdil, Önder; 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.