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  • [ X ]
    Öğe
    Ni(II), Zn(II), and Fe(III) complexes derived from novel unsymmetrical salen-type ligands: preparation, characterization and some properties
    (Taylor & Francis Ltd, 2022) Dilmen Portakal, Eylem; Kaya, Yeliz; Demirayak, Emire; Karacan Yeldir, Elif; Ercag, Ayse; Kaya, İsmet
    By using a half-salen ligand (HL) and substituted salicylaldehydes, new unsymmetrical salen-type ligands (H2L1, H2L2, and H2L3) and their Ni(II), Zn(II) and Fe(III) complexes were synthesized. The compounds were characterized based on elemental analysis, IR, H-1 NMR, X-ray diffraction (for HL), spectroscopy, mass spectrometry, magnetic moment, molar conductance measurements, and thermal analysis (TGA). The unsymmetrical salen ligands, during complexation, are attached to the metal by two imine nitrogen atoms and two phenolic oxygen atoms in all complexes; in the Fe(III) complexes, the fifth coordination is completed by chloride. Square planar geometry or distorted square planar geometry for [NiL1-3], [ZnL1-3], and square pyramidal geometry for [FeL1-3Cl] are proposed. Conductance measurements suggest non-electrolytic nature of the metal complexes. Thermogravimetric analysis showed that the complexes exhibit higher stability than the ligands. The electrochemical properties of the compounds were studied by cyclic voltammetry. HOMO-LUMO energy levels and electrochemical band gaps (E '(g)) were calculated. The solid state electrical conductivity of the iodine-doped compounds was measured and their semiconductor properties were determined. In addition, fluorescence properties of ligands and Zn(II) complexes were investigated.
  • Küçük Resim
    Öğe
    Synthesis, characterization, and investigation of some properties of the new symmetrical bisimine Ni(II), Zn(II), and Fe(III) complexes derived from the monoimine ligand
    (Wiley, 2021) Portakal, Eylem Dilmen; Kaya, Yeliz; Demirayak, Emire; Yeldir, Elif Karacan; Ercağ, Ayşe; Kaya, İsmet
    The new symmetrical bisimine (ONNO donor, salen type) Ni(II), Zn(II), andFe(III) complexes were synthesized in one step from metal ions and mon-oimine ligand (HL: 4-amino-3-{[(2-hydroxynaphthalen-1-yl)methylidene]amino}phenyl)(phenyl)methanone). The complexes were characterized by ana-lytical, spectral, conductance, magnetic, and thermal data. According to theseanalysis results, while the bisimine ligand, spontaneously forming during com-plexation, is attached to the metal by two nitrogen atoms and two phenolicoxygen atoms (N2O2) in all complexes, in the Fe(III) complex, the fifth coordi-nation is completed by the chlorine molecule. A square pyramidal geometryfor [FeLCl] and a square planar geometry for [NiL], [ZnL] were proposed. Thethree-dimensional structure of [FeLC1] was also evaluated by single-crystal X-ray diffraction, and the square pyramidal structure was clearly revealed. Themolar conductivity data of the complexes confirmed their nonelectrolyticnature. Poly(imine) (PL) was obtained by the oxidative polymerization reactionof HL, and some of its properties were investigated. The electrochemical prop-erties of the ligand and the complexes were studied by means of cyclicvoltammetry. Highest and lowest occupied molecular orbital (HOMO-LUMO)energy levels and electrochemical band gaps were calculated. The ther-mogravimetric analysis (TGA) and differential thermal analysis (DTA) of thesynthesized compounds were carried out. TGA results showed that the thermalstability of the complexes is high. The solid-state electrical conductivities of theiodine doped states of the synthesized compounds were measured by the four-point probe technique. PL has approximately 35 times higher electrical con-ductivity than the HL and complexes. Fluorescence-sensor properties of HLwere also investigated and predicted that HL could be a selective fluorescenceprobe for Pb2+
  • [ X ]
    Öğe
    The monomers and polymers of azomethine-based thiocarbohydrazones: Fluorescent activities, fluorescence quantum yields of polymers in water and DMF solutions
    (Elsevier, 2022) Kaya, İsmet; Temizkan, Kevser; Kaya, Yeliz; Ercag, Ayse
    In this study, a family of azomethine-based thiocarbohydrazone monomers and polymers prepared and their structurally characterized by FT-IR, 1H-13C NMR and UV-Vis techniques. The electrochemical behaviors, fluorescent activities, thermal characteristics, antioxidant effectiveness of synthesized compounds were determined by cyclic voltammetry (CV), fluorescence (FL) spectroscopy, thermogravimetric-differential thermal analysis (TG-DTA), differential scanning calorimeter (DSC) and CUPRAC techniques, respectively. Fluorescence quantum yields of Poly-SATCH, Poly-BSATCH, Poly-MSATCH, Poly-NATCH were calculated to be 4.1, 9.4, 11.4 and 7.4 % in 0.025 mg mL-1 concentrations in DMF solutions in the range of 3 nm slit at 440, 420, 400 and 340 nm, respectively. The antioxidant values of monomer and polymers were changed between 0.30 +/- 0.029 and 3.54 +/- 0.719 against CUPRAC technique. The glass transition temperatures of Poly-SATCH, Poly-BSATCH, PolyMSATCH and Poly-NATCH were found to be 116, 134, 138 and 139, respectively.