Yazar "Dogan, F." seçeneğine göre listele

Listeleniyor 1 - 5 / 5
  • [ X ]
    Öğe
    Nonisothermal decomposition kinetics of chromium-polyacrylate complexes prepared from aged Cr(III) solutions
    (Wiley, 2007) Dogan, F.; Ozturk, Oe. F.; Yurekli, M.; Ay, A. N.; Kose, D. A.
    Thermogravimetric studies of poly(acrylic acid) (PAA) and its chromium-polyacrylate complexes prepared from Cr(III) solutions aged for different times were undertaken. Six kinetic methods were used to investigate the thermal decomposition behavior of these materials. The applied methods were the Coats-Redfern, Horowitz-Metzger, MacCallum-Tanner, van Krevelen, Madhusudanan-Krishnan-Ninan, and Criado methods. The activation energy values obtained with the Coats-Redfern, Horowitz-Metzger, and MacCallum-Tanner methods were in good agreement with one another, and those obtained with the van Krevelen and Madhusudanan-Krishnan-Ninan methods were found to be 10-20 kJ/mol larger. The apparent activation energies increased for the complexes prepared from Cr(III) solutions aged for longer times. An analysis of the experimental results suggested that the actual decomposition mechanisms of PAA and the metal-polymer complexes were a D-n deceleration type. (C) 2007 Wiley Periodicals, Inc.
  • [ X ]
    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.
  • [ X ]
    Öğe
    Thermal studies of Co(II), Ni(II) and Cu(II) complexes of N,N'-bis(3,5-Di-t-butylsalicylidene)ethylenediamine
    (Springer, 2009) Dogan, F.; Ulusoy, M.; Ozturk, O.-F.; İsmet, Kaya; Salih, B.
    The thermal decomposition kinetics of sterically hindered salen type ligand (L) and its metal complexes [M=Co(II), Ni(II), Cu(II)] were investigated by thermogravimetric analysis. A direct insertion probe-mass spectrometer (DIP-MS) was used for the characterization of metal complexes of L and all fragmentations and stable ions were characterized. The thermogravimetry and differential thermogravimetry (TG-DTG) plots of salen type salicylaldimine ligand and complexes showed a single step. The kinetic analysis of thermogravimetric data was performed by using the invariant kinetic parameter method (IKP). The values of the invariant activation energy, E (inv) and the invariant pre-exponential factor, A (inv), were calculated by using Coats-Redfern (CR) method. The thermal stabilities and activation energies of metal complexes of sterically hindered salen type ligand (L) were found as Co(II)> Cu(II)> Ni(II)> L and E (Cu)> E (Ni)> E (Co)> L. Also, the probabilities of decomposition functions were investigated. The diffusion functions (D (n)) are most probable for the thermal decomposition of all complexes.
  • [ X ]
    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.
  • [ X ]
    Öğe
    Thermogravimetric Study of Ionic Pt(II) Complexes Containing Bis(diphenylthiophosphinyl)methane
    (Polish Chemical Soc, 2009) Dogan, F.; Irisli, S.
    The TG-DTG and DTA study of dipositive platinum(II)complexes of the general formula [Pt(L-L)(dppmS(2))](ClO(4))(2), where dppmS(2) = Ph(2)P(S)CH(2)P(S)Ph(2) and L-L = dppm (Ph(2)PCH(2)PPh(2)), dppe (Ph(2)PCH(2)CH(2)PPh(2)), and dppp (Ph(2)PCH(2)CH(2)CH(2)PPh(2)), were studied by thermogravimetric analysis from ambient temperature to 1000 degrees C in nitrogen atmosphere. The decomposition occurred in one stage for [Pt(L-L)dppmS(2)](ClO(4))(2), [Pt(L-L)dpppS(2)](ClO(4))(2) and [Pt(L-L)dppmS(2)](ClO(4))(2) complexes. The values of activation energy, E, frequency factor, A, reaction order, n, entropy change, Delta S(not equal), enthalpy change, Delta H(not equal), and Gibss free energy change, Delta G(not equal), of the thermal decomposition were calculated by means of Coats-Redfern method (CR), MacCallum-Tanner method (MC) and van Krevelen method (vK). The activation energy values obtained by CR, MC and vK methods were in good agreement with each other.