Yazar "Cetinkaya, B." seçeneğine göre listele

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    Öğe
    Copper(II) and cobalt(II) complexes of 2,6-diacetylpyridine bis(O-methyloxime): A theoretical investigation
    (Pleiades Publishing Inc, 2012) Ozdemir, N.; Dayan, O.; Dincer, M.; Cetinkaya, B.
    The molecular geometries and vibrational frequencies of the title compounds in the ground state are calculated using the Hartree-Fock (HF) and density functional theory (DFT/B3LYP) methods with the LANL2DZ basis set and compared with the experimental data. The calculated results show that the optimized geometries can well reproduce the crystal structural parameters, and the theoretical vibrational frequencies show good agreement with the experimental values. The energetic behavior of the title compounds in solvent media is examined using the B3LYP method with the LANL2DZ basis set by applying the Onsager and polarizable continuum model (PCM). In addition, molecular electrostatic potential (MEP) and frontier molecular orbital (FMO) analyses of the title compounds are investigated by theoretical calculations.
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    Öğe
    Thermal analysis study of imidazolinium and some benzimid azolium salts by TG
    (Springer, 2008) Dogan, F.; Guelcemal, S.; Yuerekli, M.; Cetinkaya, B.
    The imidazolinium and benzimidazolium bromide salts with pentafluor substituents on N atom were synthesized. The structures of imidazolinium and benzimidazolium bromide salts obtained were conformed by H-1 and C-13 NMR, F-19 NMR and elemental analysis. It was found that pyrolytic decomposition occurs with melting in salts. The imidazolinium and benzimidazolium bromide salts were studied by TG-DTG and DTA from ambient temperature to 1000 degrees C in nitrogen atmosphere. The decomposition occurred mainly in one stage and the values of activation energy E, frequency factor A, reaction order n, enthalpy change Delta H-#, entropy change Delta S-# and Gibbs free energy Delta G(#), of the thermal decomposition were calculated by means of Coats-Redfern (CR), MacCallum-Tanner (MC) and van Krevelen (vK) methods. The activation energy value obtained by CR and MC methods were in good agreement with each other while those obtained by vK were found to be 10-12 kJ mol(-1) larger.
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    Öğe
    Thermal study of ruthenium(II) complexes containing pyridine-2,6-diimines
    (Springer, 2008) Dogan, F.; Dayan, O.; Yurekli, M.; Cetinkaya, B.
    Thermal behaviors of mono- and binuclear Ru(II)-pydim complexes: [PydimCl(2)RuL] (Pydim: pyridine-2,6-diimine; 2: L=NCMe; 3: L=PPh3) and [PydiMCl(2)Ru(L-L)RuCl(2)Pydim] (4: L-L=pyrazine; 5: L-L=4,4'-bipyridine) have been studied in nitrogen atmosphere using TG/DTG and DTA techniques. The decompositions of complexes occur in stepwise. The values of activation energy, Ea, and reaction order, n of the thermal decomposition were calculated by means of several methods such as Coats-Redfern (CR), MacCallum-Tanner (MT), Horowitz-Metzger (HM), van Krevelen (vK), Madhusudanan-Krishnan-Ninan (MKN) and Wanjun-Yuwen-Hen-Cunxin (WYHC) based on the single beating rate. Most appropriate method was determined for each decomposition step according to the least-squares linear regression.