Yazar "Zeyrek, Celal Tugrul" seçeneğine göre listele

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    A Schiff base colorimetric probe for real-time naked-eye detection of biologically important fluoride and cyanide ions: Single crystal, experimental, theoretical, biological and antioxidant studies
    (Elsevier, 2020) Unver, Huseyin; Boyacioglu, Bahadir; Demir, Neslihan; Zeyrek, Celal Tugrul; Yıldız, Mustafa
    The synthesis and characterization of a Schiff base (E)-2-((3,5-bis(trifluoromethyl)phenylimino)methyl)4-methylphenol from the reaction of 2-hydroxy-5-methylbenzaldehyde with 3,5-bis(trifluoromethyl) aniline has been studied using X-ray single-crystal techniques and compared to the results from theoretical calculations using density functional theory (DFT). We have investigated the antimicrobial activities of the title compound for their minimum inhibitory concentration (MIC). We have also examined the interactions with DNA by using the UV-Visible and agarose gel electrophoresis methods. It is shown that the title compound interacts with CT-DNA via electrostatic binding. The antioxidant activity of the title compound was measured by using the DPPH method. It is furthermore shown that it indicates lower antioxidant activity than butylated hydroxytoluene (BHT). It is also found that activity remained constant with increasing compound concentration. We have also investigated the colorimetric response of the title compound in dimethyl sulfoxide (DMSO) to the addition of an equivalent amount of anions (F-, Br-, I-, CN-, SCN-, ClO4-, HSO4-, AcO-, H2PO4 and OH-). In this context, while the addition of Fand CN anions into the solution containing the title compound resulted in a significant colour change, the addition of Br-, I-, SCN-, ClO4-, HSO4-, AcO-, H2PO4 and OH anions resulted in no colour change. In the presence of these anion solutions, only Fand CN solutions underwent impressive colour change detectable with the naked eye from colourless to orange-red and purple, and orange and blue-violet in both daylight and UV light, respectively. The most discernible colour change in the Schiff base was caused by Fand CN-, which demonstrated that the Schiff base could be used to selectively detect Fand CN-. Also, various sensor applications of Schiff base were investigated. For this, the alumina oxide sheet and filter paper impregnated with the title compound were used. (C) 2020 Elsevier B.V. All rights reserved.
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    Experimental and theoretical characterization of the 2-(4-bromobenzyl)-5-ethylsulphonyl-1,3-benzoxazole
    (Elsevier, 2015) Zeyrek, Celal Tugrul; Unver, Huseyin; Arpaci, Ozlem Temiz; Polat, Kamran; Iskeleli, Nazan Ocak; Yıldız, Mustafa
    Synthesis, crystal structure, Fourier transform infrared spectroscopy (FT-IR) and quantum mechanical studies of the 2-(4-bromobenzyl)-5-ethylsulphonyl-1,3-benzoxazole (C16H14NO3SBr) have been reported. The molecular structure obtained from X-ray single-crystal analysis of the investigated compound in the ground state has been compared using Hartree-Fock (HF) and density functional theory (DFT) with the functional B3LYP and B1B95 using the 6-311++G(d,p) basis set. In addition to the optimized geometrical structures, atomic charges, molecular electrostatic potential (MEP), natural bond orbital (NBO), nonlinear optical (NLO) effects and thermodynamic properties of the compound have been investigated by using DFT. The potential energy surface (PES) scans about four important torsion angles are performed by using B3LYP/6-311++G(d,p) level of theoretical approximation for the compound. The experimental (FT-IR) and calculated vibrational frequencies (using DFT) of the title compound have been compared. The total molecular dipole moment (mu), linear polarisability (alpha), and the first-order hyperpolarisability (beta) were predicted by using DFT with different basis sets 6-31G(d), 6-31+G(d,p), 6-31++G(d,p), 6-311+G(d) and 6-311++G(d,p) for investigating the effects of basis sets on the NLO properties. Our computational results yield that beta(tot) for the title compound is greater than those of urea. The standard thermodynamic functions were obtained for the title compound with the temperature ranging from 200 to 450 K. (C) 2014 Elsevier B.V. All rights reserved.
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    Experimental, DFT Calculation, Biological Activity, Anion Sensing Application Studies and Crystal Structure of (E)-4-[(pyridin-3-ylimino)methyl]benzene-1,3-diol
    (Springer/Plenum Publishers, 2018) Unver, Huseyin; Boyacioglu, Bahadir; Zeyrek, Celal Tugrul; Yolal, Devrim; Yıldız, Mustafa; Yildirim, Nuray; Demir, Neslihan
    Crystallographic and spectroscopic studies of (E)-4-[(pyridin-3-ylimino)methyl]benzene-1,3-diol have been performed. Optimized molecular structure, conformational analysis, theoretical vibrational band assignments, nonlinear optical effects, UV-Vis, properties have also been investigated by using density functional theory with the functional B3LYP using the 6-311++G(d,p) basis set. The antimicrobial activities of the compound were investigated for its minimum inhibitory concentration. The colorimetric response of the Schiff base receptors was investigated before and after the addition of an equivalent amount of each anion to evaluate anion recognition properties. A new Schiff base was prepared and characterized. Experimental and theoretical studies on a new Schiff base have been reported. The tautomeric stability of the compound was investigated by experimental and theoretical (DFT). The nonlinear optical (NLO) effects of the compound was predicted using DFT. The antimicrobial activity and anion-sensor properties of the compound were examined. [GRAPHICS] .
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    Synthesis, biological activity, DNA binding and anion sensors, molecular structure and quantum chemical studies of a novel bidentate Schiff base derived from 3,5-bis(triflouromethyl)aniline and salicylaldehyde
    (Elsevier, 2015) Yıldız, Mustafa; Karpuz, Ozge; Zeyrek, Celal Tugrul; Boyacioglu, Bahadir; Dal, Hakan; Demir, Neslihan; Yildirim, Nuray
    Synthesis, biological activity, spectroscopic and crystallographic characterization and density functional theory (DFT) studies of the Schiff base 3,5-bis(triflouromethyl)aniline and salicylaldehyde are reported. It crystallizes as a monoclinic space group P2(1)/c with a = 7.7814(3)angstrom, b = 26.8674(9)angstrom, c = 7A520(2) angstrom, V = 1379.98(8), Z = 4, D-c = 1.6038 g cm(-3), and mu = 0.156 mm(-1). The molecular structure obtained from X-ray single-crystal analysis of the investigated compound in the ground state was compared using Hartree-Fock (HF) and density functional theory (DFT) with the functionals B3LYP and B1B95 using the 6-311++G(d,p) basis set. The antimicrobial activities of the compound were investigated for its minimum inhibitory concentration (MIC). The interaction of the Schiff base with calf thymus DNA was investigated using UV-visible spectra. The colorimetric response of the Schiff base receptors in DMSO was investigated before and after the addition of an equivalent amount of each anion to evaluate the anion recognition properties. (C) 2015 Elsevier B.V. All rights reserved.
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    Synthesis, characterization, and evaluation of (E)-methyl 2-((2-oxonaphthalen-1(2H)-ylidene)methylamino)acetate as a biological agent and an anion sensor
    (Pergamon-Elsevier Science Ltd, 2016) Zeyrek, Celal Tugrul; Boyacioglu, Bahadir; Yıldız, Mustafa; Unver, Hilseyin; Yolal, Devrim; Demir, Neslihan; Elmali, Ayhan
    An amino acid based and bidentate Schiff base, (E)-methyl 2-((2-oxonaphthalen-1(2H)-ylidene)methylamino)acetate (ligand), was synthesized from the reaction of glycine-methyl ester hydrochloride with 2-hydroxy-l-naphthaldehyde. Characterization of the ligand was carried out using theoretical quantum -mechanical calculations and experimental spectroscopic methods. The molecular structure of the compound was confirmed using X-ray single-crystal data, NMR, FTIR and UV-Visible spectroscopy, which were in good agreement with the structure predicted by the theoretical calculations using density functional theory (DFT). Antimicrobial activity of the ligand was investigated for its minimum inhibitory concentration (MIC) to several bacteria and yeast cultures. UV-Visible spectroscopy studies also shown that the ligand can bind calf thymus DNA (CT-DNA) electrostatic binding. In addition, DNA cleavage study showed that the ligand cleaved DNA without the need for external agents. Energetically most favorable docked structures were obtained from the rigid molecular docking of the compound with DNA. The compound binds at the active site of the DNA proteins by weak non-covalent interactions. The colorimetric response of the ligand in DMSO to the addition of equivalent amount of anions (F-, Br-, I-, CN-, SCN-, ClO4-, HSO4-, AcO-, H2PO4-, N-3(-) and OH-) was investigated and the ligand was shown to be sensitive to CN- anion. (C) 2016 Elsevier Ltd. All rights reserved.
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    Synthesis, Crystal Structure, Anion Sensing Applications and DFT Studies of (E)-2-[(3,5-Bis(trifluoromethyl)phenylimino)methyl]-4-chlorophenol
    (Springer/Plenum Publishers, 2019) Unver, Huseyin; Zeyrek, Celal Tugrul; Boyacioglu, Bahadir; Yıldız, Mustafa; Demir, Neslihan; Elmali, Ayhan
    We report the synthesis and characterization, colorimetric anion sensors properties, density functional theory (DFT) calculation studies of a Schiff base (E)-2-[(3,5-bis(trifluoromethyl)phenylimino)methyl]-4-chlorophenol. The molecular structure of the title compound was experimentally determined using X-ray single-crystal data and was compared to the structure predicted by theoretical calculations using DFT. The experimental and calculated data (using DFT) of the title compound have been compared. To investigate the tautomeric stability, some properties such as total energy, HOMO and LUMO energies, the chemical hardness (eta), the ionization potential, the electron affinity, the absolute electronegativity (chi), the absolute softness (sigma) of the compound were obtained at B3LYP/6-311++G(d,p) level in the gas phase and solvent phase. The calculated results showed that the enol-imine form of the compound was more favorite than keto-amine form. The colorimetric response of the Schiff base receptors in DMSO was investigated. [GRAPHICS] .
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    Synthesis, molecular structure, spectroscopic and theoretical studies on E-2-ethoxy-4-[(4-ethoxyphenylimino)methyl]phenol
    (Elsevier, 2015) Zeyrek, Celal Tugrul; Alpaslan, Gokhan; Alyar, Hamit; Yıldız, Mustafa; Dilek, Nefise; Unver, Huseyin
    Synthesis, crystallographic characterization, spectroscopic (FT-IR) and density functional modelling studies of a new Schiff base E-2-ethoxy-4-[(4-ethoxyphenylimino)methyllphenol C17H19NO3 have been reported. The molecular structure obtained from X-ray single-crystal analysis of the investigated compound in the ground state has been compared using Hartree Fock (HF) and density functional theory (DFT), B3LYP and B1B95 functional with the 6-311++G(d,p) basis set. In addition to the optimized geometrical structures, atomic charges, molecular electrostatic potential (MEP), natural bond orbital (HBO), nonlinear optical (NLO) effects and thermodynamic properties of the compound have been investigated by using DFT calculations. The electronic properties of the title compound in solvent media were also examined using the DFT calculations. The potential energy surface (PES) scans about important torsion angles are performed by using B3LYP/6-311++G (d,p) level of theoretical approximation for the compound. The experimental (FT-IR) and calculated vibrational frequencies (using DFf calculations) of the title compound have been compared. The predicted NLO properties of the compound which calculated by the B3LYP method with 6-31G(d), 6-31+G(d,p), 6-31++G(d,p), 6-311+G(d) and 6-311++G(d,p) basis sets are greater than ones urea. The standard thermodynamic functions were obtained for the title compound with the temperature ranging from 200 to 450 K. (C) 2015 Elsevier B.V. All rights reserved.
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    Synthesis, Quantum Chemical Calculations and Molecular Docking Studies, Biological and Anion Sensor Properties of (E)-4-[(4-ethoxy-phenylimino)methyl]-2-methoxyphenol
    (Croatian Chemical Soc, 2018) Zeyrek, Celal Tugrul; Unver, Huseyin; Boyacioglu, Bahadir; Demir, Neslihan; Yapar, Gonul; Dal, Hakan; Yıldız, Mustafa
    We report the synthesis and characterization, biological activity, DNA binding, colorimetric anion sensor properties, computational (HF) and molecular docking studies of a novel Schiff base (E)-4-[(4-ethoxyphenylimino)methyl]-2-methoxyphenol. The molecular structure of the title compound was experimentally determined using spectroscopic data and was compared to the structure predicted by theoretical calculations using density functional theory (DFT). In addition, atomic charges, molecular electrostatic potential (MEP), nonlinear optical (NLO) effects, the potential energy surface (PES) scans about two important torsion angles and thermodynamic properties of the title compound were predicted using DFT. The antimicrobial activity of the compound was investigated for minimum inhibitory concentration. UV-Vis spectroscopy studies of the interactions between the compound and calf thymus DNA (CT-DNA) showed that the compound interacts with CT-DNA via intercalative binding. The colorimetric response of the Schiff base receptors in DMSO was investigated. The most discernable color change in the Schiff base was caused by CN-, which demonstrated that the ligand can be used to selectively detect CN-.
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    Synthesis, spectral and quantum chemical studies and use of (E)-3-[(3,5-bis(trifluoromethyl)phenylimino)methyl]benzene-1,2-diol and its Ni(II) and Cu(II) complexes as an anion sensor, DNA binding, DNA cleavage, anti-microbial, anti-mutagenic and anti-cancer agent
    (Elsevier, 2016) Unver, Huseyin; Boyacioglu, Bahadir; Zeyrek, Celal Tugrul; Yıldız, Mustafa; Demir, Neslihan; Yildrim, Nuray; Karaosmanoglu, Oguzhan
    We report the synthesis of a novel Schiff base (E)-3-[(3,5-bis(trifluoromethyl) phenylimino)methyll benzene-1,2-diol from the reaction of 2,3-dihydroxybenzaldehyde with 3,5-bis(trifluoromethyl)aniline, and its Ni(II) and Cu(II) complexes. The molecular structure of the Schiff base was experimentally determined using X-ray single-crystal data and was compared to the structure predicted by theoretical calculations using density functional theory (DFT), Hartree-Fock (HF) and Moller-Plesset second-order perturbation (MP2). In addition, nonlinear optical (NLO) effects of the compound was predicted using DFT. The antimicrobial activities of the compounds were investigated for their minimum inhibitory concentration. UV-Vis spectroscopy studies of the interactions between the compounds and calf thymus DNA (CT-DNA) showed that the compounds interacts with CT-DNA via intercalative binding. A DNA cleavage study showed that the Cu(II) complex cleaved DNA without any external agents. The compounds inhibited the base pair mutation in the absence of S9 with high inhibition rate. In addition, in vitro cytotoxicity of the Ni(II) complex towards HepG2 cell line was assayed by the MIT method. Also, the colorimetric response of the Schiff base in DMSO to the addition of equivalent amount of anions (F-, Br-, I-, CN-, SCN-, ClO4-, HSO4-,AcO-, H2PO4-, N-3(-) and OH-) was investigated. In this regard, while the addition of F-, CN-, AcO- and OH- anions into the solution containing Schiff base resulted in a significant color change, the addition of Br-, I-, SCN-, ClO4-, HSO4-, H2PO4- and N-3(-) anions resulted in no color change. The most discernable color change in the Schiff base was caused by CN-, which demonstrated that the ligand can be used to selectively detect CN-. (C) 2016 Elsevier B.V. All rights reserved.
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    Synthesis, structure, spectroscopic (FT-IR) and density functional modelling studies of 1-[(4-ethoxyphenylimino)methyl]napthalene-2-ol
    (Taylor & Francis Ltd, 2014) Zeyrek, Celal Tugrul; Dilek, Nefise; Yıldız, Mustafa; Unver, Huseyin
    Synthesis, crystallographic characterisation, spectroscopic (Fourier transform infrared spectroscopy [FT-IR]) and density functional modelling studies of the Schiff base 1-[(4-ethoxyphenylimino)methyl]napthalene-2-ol (C19H17NO2) have been reported. The molecular structure obtained from X-ray single-crystal analysis of the investigated compound in the ground state has been compared using Hartree-Fock and density functional theory (DFT) with the 6-311++G(d,p) basis set. In addition to the optimised geometrical structures, atomic charges, molecular electrostatic potential, natural bond orbital, non-linear optical (NLO) effects and thermodynamic properties of the compound have been investigated by using DFT. The experimental (FT-IR) and calculated vibrational frequencies (using DFT) of the title compound have been compared. The solvent effect was also investigated for obtained molecular energies and the atomic charge distributions of the compound. There exists a good correlation between experimental and theoretical data for enol-imine form of the compound. The total molecular dipole moment (mu), linear polarisability (), and the first-order hyperpolarisability () were predicted by the B3LYP method with different basis sets 6-31G(d), 6-31+G(d,p), 6-31++G(d,p), 6-311+G(d) 150 and 6-311++G(d,p) for investigating the effects of basis sets on the NLO properties. Our computational results yield that (tot) for the title compound is greater than those of urea.