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Thermal analyses of coordination compounds

II. Thermal decomposition of palladium complexes with triphenylphosphine, triphenylarsine and triphenylstibine

Journal of Thermal Analysis and Calorimetry
Authors: R. Barbiéri, C. Belatto, and A. Massabni

Abstract  

The compounds [PdCl2L2] and [PdL4] (L=PPh3, AsPh3, SbP3) were studied by thermogra-vimetric and differential thermal analyses in air. The residues of thermal decomposition consist of metallic palladium, except in the case of the complexes containing SbPh3, when the residues are palladium and antimony mixtures in appropriate proportions with respect to the stoichiometry of the related complexes.

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study the complexes in material science technology. The term thermal analyses incorporate the technique in which some physical parameters of the system are determined or recoded as the function of temperature [ 2 – 5 ]. Thermogravimetric analysis is one

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continuously scanned, and the obtained spectra were stored. The EI-MS were obtained at an ionizing energy value of 70 eV, an ionization current of 60 μA, with vacuum being better than 10 −6 torr. Thermal analyses (TAs) The

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Journal of Thermal Analysis and Calorimetry
Authors: Sheng-Hung Wu, Chu-Chin Hsieh, Chung-Cheng Chiang, Jao-Jia Horng, Wei-Ping Pan, and Chi-Min Shu

and mass loss rate curve for the zeolite sample under air flow are plotted in Fig. 3 . Thermal behavior of home-made zeolite by TG in N 2 or air was discovered as similar. Fig. 2 Thermal analyses of

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Summary  

This paper describes the use of the mass spectrometry (MS), thermal analyses (TA) and other physico-chemical methods to investigate the structure of two newly synthesized phenolic-iodine derivative polymeric products. These two products are formed as a result of redox-interaction of adrenaline hydrogen tartrate (AHT, I) with iodate (IO- 3) and periodate (IO- 4). The characterization of the two products were achieved satisfactorily by using the above tools and their proposed general formulae, were found to be C52H67O36N4I (AHT- IO- 3, II) and C26H34O18N2I2(AHT- IO- 4, III). The fragmentation behavior of the main compound (AHT) in MS and TA (TG and DTA) techniques was investigated and compared. The results obtained were used to explain the fragmentation of the products AHT- IO- 3and AHT- IO- 4in mass spectrometry and thermal analyses techniques. The stabilities of different fragments were discussed. The results indicate that the two techniques are supporting each other in which the mass spectrometry provides the structural information in gas phase while the thermal analyses provides the quantitative fragmentation in the solid-state.

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Abstract  

The effect of calcium hydroxide (CH) on the properties of Portland–fly ash cement pastes, at up to high-volume fly ash mixes has been investigated using normal consistency, setting time, compressive strength, thermal analysis and scanning electron microscope. CH as an additive material (5 and 10 wt%), lignite fly ash (FA) up to 50 wt% was used to produce Portland cement (PC)–FA–CH pastes at w/PC + FA ratio of 0.5. Water requirement for normal consistency was found to increase with increasing CH content while a decrease in initial setting time was found. Furthermore, the compressive strengths of all FA mixes with CH were found to be higher than the mixes without CH. Thermal analysis and scanning electron microscope were used to study the hydration of PC–FA–CH system. The results showed that the first phase transition detected by thermal analyses was attributed to ettringite, calcium silicate hydrate, gehlenite hydrate and was found to be higher in PC–FA–CH mixes than in pure Portland–FA cement paste resulting in an increase in compressive strength. Moreover, the hydration phases were also found to increase with increasing curing time. Overall, the results show that the additional of 5 wt% CH in Portland–FA mixes especially at high-volume FA mixes was found to accelerate FA pozzolanic reaction at early ages (7 and 28 days), resulting to an increase in compressive strength.

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Thermal analysis as an analytical tool has been applied to the study of suspended liquid and solid matter in air. The aerosol is heated in a glass pipe, and the light scattering coefficient is used for thein situ detection of aerosol. Results of thermal analysis of the Los Angeles smog, and of St. Louis aerosol on dry and humid days, are presented, all indicating distinctly different thermo-nephelograms. On polluted days in St. Louis, over 50% of the light scattering coefficient is lost at about 100‡, which indicates the presence of H2SO4.

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Abstract  

The compounds [(LR2Sn)2O] {R=CH3 (Me), n-C4H9(Bn); L=C6H5CH(OH)COO}were studied by thermogravimetric and differential scanning calorimetry in a dynamic atmosphere of helium. The thermal decomposition mechanisms are similar for both compounds and occur in two consecutive steps. The TG curves of the complexes suggest the liberation of the ligand L in the first step, with probable formation of a tin oxide R2SnO intermediate. At the end of the second step free tin is obtained in accordance with the stoichiometry of the related compounds. An inverse relation betweenΔH fusion and solubility of the compounds suggests a polymeric structure for the compound with Bn ligand in relation to the compound with M ligand.

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Abstract  

The paper presents studies on synthetic sinters of given basicities (CaO/SiO2 1.7–2.1). These multicomponent systems include not only doped iron oxides but calcium ferrites and numerous silicate phases as well. Investigatons were carried out by complex research methods, first of all by thermal analysis. Reduction processes of the sinters were observed by the methods of polythermal analysis in CO/CO2 atmosphere. The effect of mineral composition on physico-chemical properties of the sinters has been determined.

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Abstract  

The physico-geometric kinetics for the solid-state reactions by thermoanalytical (TA) measurements were reexamined by focusing some fundamental aspects: (1) the fundamental kinetic equation, (2) the kinetic model function, (3) the fractional reaction α, and (4) the apparent kinetic parameters. It was pointed out that some pitfalls in the practical kinetic study are originated by the disagreement between the kinetic information from the TA measurements and the theory of the physico-geometric kinetics. In order to increase the degree of coordination between the theory and practice, several attempts were made from both the theoretical and experimental points of views. The significance of the apparent kinetic parameters was discussed with a possible orientation for obtaining the reliable kinetic parameters.

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