Synthetic, Characterization and Decomposition Studies of Indium Sulfide Precursors

1995 ◽  
Vol 410 ◽  
Author(s):  
Rodney D. Schluter ◽  
Henry A. Luten ◽  
William S. Rees
Keyword(s):  
Thermal Decomposition ◽  
Coordination Number ◽  
Synthetic Methods ◽  
Indium Sulfide ◽  
Chelating Ligands ◽  
Metal Halides ◽  
Liquid Precursor ◽  
Thermogravimetric Data ◽  
Metathesis Reactions ◽  
Reversible Formation

ABSTRACTThe synthesis, characterization and decomposition of several indium thiolates containing the bulky substituted aryl ligand 2,4,6-i-Pr 3C6H2 (Ar′) or the internally chelating ligands 2-CH3O,5-CH3C6H3 (Ar″) and o-C6H4CH2N(CH3)2 (Ar"‘) are described. Two synthetic methods have been utilized: metathesis reactions between lithium thiolates and the appropriate metal halides and the addition of elemental metal to diaryl disulfides. The thermal decomposition of each indium precursor results in the formation of 1n2S3, based on thermogravimetric data. The homoleptic compound In(SAr′)3 can be isolated as a yellow oil. This liquid precursor has been derivatized by the reversible formation of acetonitrile and tetrahydrofuran adducts. Although, the molecule exists as a monomer in both adducts, the coordination number of the metal and he orientation of the ligands are markedly different. The internally chelating In(SAr″)3 and In(SAr.″′)3 adopt contrasting dimeric and monomeric structures respectively.

scholarly journals Fique as a Sustainable Material and Thermal Insulation for Buildings: Study of Its Decomposition and Thermal Conductivity

2021 ◽  
Vol 13 (13) ◽  
pp. 7484
Author(s):  
Gabriel Fernando García Sánchez ◽  
Rolando Enrique Guzmán López ◽  
Roberto Alonso Gonzalez-Lezcano
Keyword(s):  
Thermal Conductivity ◽  
Thermal Decomposition ◽  
Thermal Insulation ◽  
Model Fitting ◽  
Good Alternative ◽  
Negative Effects ◽  
Thermal Insulator ◽  
Fitting Method ◽  
Thermogravimetric Data ◽  
Reduce Energy Consumption

Buildings consume a large amount of energy during all stages of their life cycle. One of the most efficient ways to reduce their consumption is to use thermal insulation materials; however, these generally have negative effects on the environment and human health. Bio-insulations are presented as a good alternative solution to this problem, thus motivating the study of the properties of natural or recycled materials that could reduce energy consumption in buildings. Fique is a very important crop in Colombia. In order to contribute to our knowledge of the properties of its fibers as a thermal insulator, the measurement of its thermal conductivity is reported herein, employing equipment designed according to the ASTM C 177 standard and a kinetic study of its thermal decomposition from thermogravimetric data through the Coats–Redfern model-fitting method.

scholarly journals AN INNOVATE METHOD OF THERMOGRAVIMETRIC DATA ANALYSIS

2021 ◽  
Vol 64 (3) ◽  
pp. 24-32
Author(s):  
Mihail V. Mal’ko ◽  
Sergej V. Vasilevich ◽  
Andrey V. Mitrofanov ◽  
Vadim E. Mizonov
Keyword(s):  
Experimental Data ◽  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
Kinetic Parameters ◽  
Calculation Method ◽  
Kinetic Calculation ◽  
Pyrolysis Mechanism ◽  
Total Mass Loss ◽  
Thermogravimetric Data ◽  
Heavy Tar

The objective of the study is to examine the Coats-Redfern approximation and to propose an innovative kinetic calculation method for the complex process of the heavy tar thermal decomposition under non-isothermal process. The thermal decomposition process was examined using the thermogravimetric analysis. There are several kinetic models proposed to analyze pyrolysis mechanism in terms of the formal reaction. In this manner, the kinetic parameters of the pyrolysis process can be evaluated based on total mass loss (thermogravimetric analysis –TGA). The TGA procedures can be conducted with isothermal or non-isothermal conditions, but the experimental data obtained according to this procedure have to be transformed into appropriate correlation. The obtained results have shown that the reaction takes place within temperature range of 540 K to 700 K and the inductive period of the process is about 224 min. Kinetic parameters were estimated with using of the conventional Coats-Redfern method. A new kinetic calculation method has been designed to provide a less laboriousness of identifications procedures compared with Coats-Redfern approximation and to take into account an induction time of the process. As the outcome of this study, it was shown that the kinetic parameters estimated with using of the proposed model-fitted method gives the more appropriate correlation in comparison with the conventional Coats-Redfern method. The proposed method uses the Coats-Redfern algorithm for evaluation of the reaction mechanism, but the value of the constant rate is defined directly from experimental data on the conversion rate.

Wechselwirkungen in Molekülkristallen, 156 [1, 2]. Kristallzüchtung und Strukturbestimmung von (Imidodiphosphat)-Alkalisalzen mit Kationen niedriger und hoher Koordinationszahlen / Interaction in Molecular Crystals, 156 [1, 2]. Crystal Growth and Structure Determination of Alkali(imidodiphosphate) Salts with Cations of Low and High Coordination Numbers

2000 ◽  
Vol 55 (9) ◽  
pp. 773-784 ◽  
Author(s):  
Hans Bock ◽  
Erik Heigel ◽  
Norbert Nagel
Keyword(s):  
Crystal Growth ◽  
Coordination Number ◽  
Molecular Crystals ◽  
Chelating Ligands ◽  
Chain Polymer ◽  
Coordination Numbers ◽  
Structural Differences ◽  
A Chain ◽  
High Coordination

Imidodiphosphates ⊖N[PO(OR)2]2 and Imidodiphosphonates ⊖N[POR2]2 are effective chelating ligands for a variety of metal cations including even Na⊕, for which a lipophilically wrapped hexameric polyion cluster has been structurally characterized. The corresponding hexameric lithium and polyrubidium ion complexes reported here exhibit considerable structural differences: The rather small Li⊕ cations of coordination number five and tetraphenylimidodiphosphate form an isolated hexameric aggregate analogous to the Na⊕ one, whereas the larger Rb⊕ with coordination number seven and (3,4-dimethylphenyl)substituents crystallizes as a chain polymer. Based on the crystal structures, the dominant Coulomb attractions between cations and anions, the spatial requirement of the ligands and the essential phenyl/phenyl interactions in their lipophilic skin are discussed

A Mössbauer study of thermal decomposition of biotites

1975 ◽  
Vol 40 (309) ◽  
pp. 79-88 ◽  
Author(s):  
C. S. Hogg ◽  
R. E. Meads
Keyword(s):  
Heat Treatment ◽  
Thermal Decomposition ◽  
Hydroxyl Group ◽  
Mössbauer Study ◽  
Octahedral Sites ◽  
M6ssbauer Effect ◽  
Thermogravimetric Data ◽  
Infra Red ◽  
Structural Breakdown ◽  
Good Agreement

SummaryThe effect of heat treatment in air at temperatures from 200°C to 1000°C of two Cornish biotites has been studied using the M6ssbauer effect in 57Fe. One of the micas was also studied after heating in vacuo.Progressive changes in the Mössbauer spectra of the materials after heat treatment can be correlated with the following processes: Oxidation of Fe2+ ions in isolated octahedral sites to give Fe3+ in the co-ordination Fe3+(OsOH); oxidation of Fe2+ ions in adjacent a-octahedral (cis OH−) sites to give Fe3+(O6); and oxidation of Fe z+ in adjacent a and b (trans OH−) sites to give either Fe3+(O5OH) or Fe3+(O6) depending on whether a shared hydroxyl group remains intact or otherwise (these processes occur at temperatures below 500°C Also, at higher temperatures, dehydroxylation of Fe3+(O5OH) to give more Fe3+ in the Fe3+(O6) configuration. Finally, in the temperature range 900 to 1000°C structural breakdown yielding α-Fe2O3 as the iron-containing phase.The results and interpretation are in good agreement with thermogravimetric data and with a previous infra-red study. The mechanism of charge diffusion in the lattice during oxidation is discussed in the light of the results.

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