Yazar "Selcuki, Nursel Acar" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    Synthesis, characterization, OFET, and DFT study of the novel ball-type metallophthalocyanines bridged with four diaminopyrimidine-dithiol
    (World Scientific Publishing Co. Pte. Ltd., 2022) Molla, Fadime; Yazici, Aysegul; Selcuki, Nursel Acar; Altindal, Ahmet; Salih, Bekir; Bekaroğlu, Özer; Ball-Type Phthalocyanines; Density Functional Theory
    Co2Pc2 (2) and Zn2Pc2 (3) were obtained in DMF and LuPc2 (4) was obtained in hexanol by the cyclotetramerization of novel diphthalonitrile (1). Synthesized compounds were characterized by FT-IR, 1H-NMR, elemental analyses, MALDI-TOF MS and UV-vis spectroscopy techniques. Optimized geometries and electronic structures for compounds 2, 3 and 4 were investigated by Density Functional Theory (DFT) and Time Dependent Density Functional Theory (TD-DFT). In compound 2, a new bond was observed between Co centers forming two Co(III) with the interaction of d orbitals. Computational and experimental UV-vis spectra in DMF were found in agreement for the investigated compounds. Vertical and adiabatic ionization potentials for the studied systems were also calculated. The gate dielectric performances of thin films obtained from these compounds were investigated by fabricating ITO/2-4/Au devices. The observed reverse bias J-V characteristics revealed that the leakage current in ITO/2-4/Au devices is because of the Poole-Frenkel effect. The effect of the gate dielectric on the OFET performance parameters was also investigated by fabricating bottom-gate top-contact OFET using pentacene as the active layer. Maximum field effect mobility was observed with the 2-based OFET device. Calculated HOMO-LUMO gap, hole reorganization energy and ionization energy have also supported the experimental results which indicate that 2 is the most suitable system for OFET devices
  • Küçük Resim
    Öğe
    Synthesis, conductivity, and ımpedance studies on metallophthalocyanines formed across adjacent rings
    (Wiley-V C H Verlag Gmbh, 2019) Sener, Sevil; Selcuki, Nursel Acar; Dumludag, Fatih; Salih, Bekir; Bekaroğlu, Özer
    The synthesis and characterization of Co-II, Zn-II, and Ni-II phthalocyanines (Pcs) 4, 5, and 6, respectively, containing two bis[2-(4-hydroxyphenyl)-2-propyl]benzene groups formed across adjacent rings at the peripheral positions are described. The Pcs were synthesized by cyclotetramerization of the previously prepared precursor 4,4 '-bis[1,3-propylbenzene-2-p-phenoxy]phthalonitrile (3) in the presence of metal salt in boiling dry DMF under a dry nitrogen atmosphere. Elemental analysis, UV-Vis, FT-IR, and H-1-NMR spectroscopy, as well as MALDI-TOF mass spectrometry techniques were used for the characterization of 4. Conductivity (dc and ac) and impedance spectroscopy (IS) measurements were performed on the films of 5 and 6 between the temperatures 293 and 523 K and frequencies 40 and100 kHz. The dc conductivity values were calculated as 2.11 x 10-(10), 3.48 x 10-(10), and 1.90 x 10-(10) S/cm for the films of 4, 5, and 6, respectively, at room temperature. Activation energy values of the films were also calculated. Conductivity (ac) results suggest that the dominant charge transport mechanisms can be explained by the hopping model depending on temperature and frequency range. From impedance spectra and Cole-Cole plots, the relaxation time in the Debye dispersion relation is considered as a distribution of relaxation time values rather than as a single relaxation time. To elucidate the structural, spectroscopic, and bonding properties of the obtained compounds, DFT/TD-DFT calculations were performed.