Thermal behaviors of N-pyrrolidine-N '-(2-chlorobenzoyl)thiourea and its Ni(II), Cu(II), and Co(III) complexes

The N-pyrrolidine-N'-(2-chlorobenzoyl)thiourea, HL, and their Ni(II), Cu(II), and Co(III) complexes (NiL2, CuL2, and CoL3) have been synthesized and characterized. The thermal decomposition reactions of all the compounds have been investigated by DTA/TG combined systems. The mass spectroscopy technique has been used to identify the products during pyrolytic decomposition. The pyrolytic final products have been analyzed by X-ray powder diffraction method. After comparison of thermogravimetric and mass results of HL, NiL2, CuL2, and CoL3, the decomposition mechanism of these compounds have been suggested. The thermal stability of the Ni(II) and Cu(II) complexes according to the thermogravimetric curves follows the sequence: NiL2 < CuL2. The values of the activation energy, E (a), have been obtained using model-free (Kissenger-Akahira-Sunose, KAS, Flyn-Wall-Ozawa, FWO, and Isoconversional) methods for all decomposition stages. The E (a) versus the extent of conversion, alpha, plots show that the values of E (a) varies as alpha. Thirteen kinetic model equations have been tested for selecting correct reaction models. The optimized value of E (a) and Arrhenius factor, A, have been obtained using the best model equation. The thermodynamic functions (Delta H*, Delta S*, and Delta G*) have been calculated using these values.WOS:0003082520000302-s2.0-8486740093

Thermal analysis of cis-(dithiocyanato)(1,10-phenanthroline-5,6-dione)(4,4'-dicarboxy-2,2'-bipyridyl)ruthenium(II) photosensitizer

20th CTAS Annual Workshop and Exhibition CTAS -- MAY 12-13, 2010 -- Mississauga, CANADA --Thermal behavior of [cis-(dithiocyanato)(1,10-phenanthroline-5,6-dione)(4,4'-dicarboxy-2,2'-bipyridyl)ruthenium(II)], cis-[Ru(L1)(L2)(NCS)(2)] (where the ligands were L1 = 1,10-Phenanthroline-5,6-dione, L2 = 4,4'-dicarboxy-2,2'-bipyridyl) was investigated by DTA/TG/DTG measurements under inert atmosphere in the temperature range of 298-1473 K as well as by XRD analysis of the final product. After making detailed analysis and comparison of thermogravimetrical and MS measurements of ruthenium complex, the decomposition mechanism of that complex was suggested. The values of activation energy and reaction order of the thermal decompositions were calculated by Ozawa Non-isothermal Method for all decomposition stages. The calculated activation energies vary in between 32 and 49 kJ mol(-1).Scientific and Technical Research Council of Turkey (TUBITAK-BAYG)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)The authors would like to thank The Scientific and Technical Research Council of Turkey (TUBITAK-BAYG) for financial support. The authors thank to Prof. Dr. Nevzat Kulcu, Dr. Gokturk Avsar (from Mersin University, Turkey), and Dr. Selma Erat (ETH-Zurich, Switzerland) for their helpful discussions.WOS:0002905788000292-s2.0-7995937811

An investigation of decomposition stages of a ruthenium polypridyl complex by non-isothermal methods

Symposium on Applications of Thermal Analysis and Calorimetry - Workshop and Exhibition (SATAC) 11th National Convention of Chemistry Teachers, India -- OCT 15-17, 2011 -- undefined, INDIA --Thermal properties of [cis-(dithiocyanato)(4,5-diazafluoren-9-one)(4,4'-dicarboxy-2,2'-bipyridyl)ruthenium(II)], [Ru(L-1)(L-2)(NCS)(2)] (where the ligands L-1 = 4,5-diazafluoren-9-one, L-2 = 4,4'-dicarboxy-2,2'-bipyridyl) have been investigated by DTA/TG/DTG measurements under inert atmosphere in the temperature range of 30-1155 degrees C. The mass spectroscopy technique has been used to identify the products during pyrolytic decomposition. The pyrolytic final products have been analyzed by X-ray powder diffraction technique. A decomposition mechanism has been also suggested for the cis-[Ru(L-1)(L-2)(NCS)(2)] complex based on the results of thermogravimetrical and mass analysis. The values of the activation energy, E* have been obtained by using model-free Kissenger-Akahira-Sunose and Flyn-Wall-Ozawa non-isothermal methods for all decomposition stages. Thirteen kinetic model equations have been tested for selecting the best reaction models. The best model equations have been determined as A2, A3, D1, and D2 which correspond to nucleation and growth mechanism for A2 and A3 and diffusion mechanism for D1 and D2. The optimized average values of E* are 31.35, 58.48, 120.85, and 120.56 kJ mol(-1) calculated by using the best model equations for four decomposition stages, respectively. Also, the average Arrhenius factor, A, has been obtained as 2.21, 2.61, 2.52, and 2.21 kJ mol(-1) using the best model equation for four decomposition stages, respectively. The Delta H*, Delta S*, and Delta G* functions have been calculated using the optimized values.WOS:0003105430000382-s2.0-8487091583

Synthesis, Characterization and Luminescence Properties of Sr3WO6:Eu3+ Phosphor

1st International Congress on Advances in Applied Physics and Materials Science (APMAS) -- MAY 12-15, 2011 -- Antalya, TURKEY -- Istanbul Kultur Univ, Gebze Inst Technol, Doga Nanobiotech Inc, Terra Lab Inc, LOT Oriel Grp, PHYWE, Delta Elekt IncSr3WO6:Eu3+ phosphor was prepared at high temperature by solid state method. The phase structure of phosphor was characterized as double perovskite structure. The cell parameters of Sr3WO6:Eu3+ were determined as a = 8.361 angstrom, b = 8.288 angstrom, c = 8.211 angstrom, alpha = beta = gamma = 89.78 degrees. The luminescence properties were studied. The results revealed that Eu3+ ions show red emission about 616 nm.WOS:0002996030000782-s2.0-8485611273