An azo compound route to spiropentane thermolysis intermediates. Formation of vibrationally excited organic molecules in the thermal decomposition of pyrazolines, and evidence concerning the distribution of excess energy in reaction products

1977 ◽  
Vol 99 (5) ◽  
pp. 1655-1657 ◽  
Author(s):  
Kelvin Kei-Wei Shen ◽  
Robert G. Bergman
Keyword(s):  
Thermal Decomposition ◽  
Organic Molecules ◽  
Excess Energy ◽  
Reaction Products ◽  
Vibrationally Excited ◽  
Azo Compound

scholarly journals Thermal Decomposition and Thermal Reaction Process of PTFE/Al/MnO2 Fluorinated Thermite

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2451 ◽  
Author(s):  
Jun Zhang ◽  
Junyi Huang ◽  
Xiang Fang ◽  
Yuchun Li ◽  
Zhongshen Yu ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Control Systems ◽  
Thermal Reaction ◽  
Reaction Process ◽  
Reaction Products ◽  
Subsequent Reaction ◽  
Comparison Results ◽  
Different Temperatures ◽  
Xrd Phase Analysis ◽  
Two Stages

To better understand the thermal decomposition and reaction process of a fluorine-containing powdery thermite, PTFE/Al/MnO2, reactions at different temperatures were investigated by the TG/DSC-MS technique. The corresponding reaction products were characterized with XRD phase analysis. Another three thermite materials, i.e., PTFE/Al, Al/MnO2, and PTFE/MnO2, were also prepared for comparison. Results showed that PTFE behaved as both oxidizer and reducer in PTFE/Al/MnO2 fluorinated thermite. The thermal decomposition and reaction process of as-fabricated ternary thermite could be divided into two stages—the mutual reaction between each of PTFE, Al, and MnO2 and the subsequent reaction produced between Al and Mn2O3/Mn3O4/MnF2. Compared with the three control systems, the specially designed ternary system possessed a shorter reaction time, a faster energy release rate, and a better heat release performance.

The thermal decomposition of diethyl ether. II. Analytical survey of the reaction products as a function of reaction conditions

1958 ◽  
Vol 245 (1240) ◽  
pp. 40-48 ◽  
Keyword(s):  
Thermal Decomposition ◽  
Rate Constants ◽  
Vapour Phase ◽  
Mass Spectrometric ◽  
Spectrometric Analysis ◽  
Reaction Products ◽  
Reaction Conditions ◽  
True Rate ◽  
Carbon Tetrafluoride ◽  
Pressure Changes

By mass-spectrometric analysis combined with vapour-phase chromatography the reaction products from the thermal decomposition of ether have been determined at various stages of the reaction (uninhibited and inhibited by nitric oxide) for initial ether pressures of 80 to 1000 mm. The effects of added hydrogen and of carbon tetrafluoride on the composition of the products have also been examined. No major changes in the chemistry of the reaction occur with these variations in conditions. Factors are given for calculating true rate constants from pressure changes accompanying the reaction. Corrected values of rate constants vary with the conditions in the same way as the values derived from uncorrected pressure changes, the correspondence being close for the uninhibited reaction.

Thermal Decomposition of Some Iron(III) Chromates

1988 ◽  
Vol 41 (2) ◽  
pp. 263 ◽  
Author(s):  
PJ Mineely
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Second Phase ◽  
Reaction Products ◽  
Mößbauer Spectroscopy

The thermal decomposition of the chromates FeOHCrO4, KFe3(CrO4)2(OH)6, Fe2(CrO4)3.H2O and Fe2(CrO4)3.3H2O have been studied by thermal analysis and Mossbauer spectroscopy. The possible presence of Fe2O(CrO4)2 as a second phase formed during the decomposition is discussed. Final products in all reactions were oxides of iron(III) and chromium(III). In addition K2Cr2O7 Was present in the reaction products for KFe3(CrO4)2(OH)6.

In-situ Raman study of the thermal decomposition of LiBH4

2009 ◽  
Vol 1216 ◽  
Author(s):  
Daniel Reed ◽  
David Book
Keyword(s):  
Thermal Decomposition ◽  
Hydrogen Storage ◽  
Peak Position ◽  
Ex Situ ◽  
Liquid Lithium ◽  
Reaction Products ◽  
Lithium Borohydride ◽  
Storage Media ◽  
Liquid Phases

AbstractWith relatively high gravimetric and volumetric hydrogen storage capacities, borohydrides have attracted interest as potential hydrogen storage media. Lithium borohydride has a maximum theoretical gravimetric hydrogen storage density of 18.4 wt%, and has been shown to be reversible when heated to 600°C in 350 bar hydrogen1. It is hoped that a greater understanding of the decomposition and reformation mechanisms, may lead to the development of LiBH4-based materials that can absorb and desorb hydrogen under less extreme conditions. However, these studies have proved a challenge: currently most in-situ investigations have used x-ray diffraction or neutron diffraction however these cannot readily give information on non-crystalline or liquid phases. The preparation of samples measured ex-situ via XRD, NMR2 and Raman3 have shown the reaction products and stable intermediates during the thermal decomposition, however, it is very difficult to detect short lived intermediate (or byproduct) species. Raman spectroscopy has the advantages that: materials with only short-range order can be analysed; and by focusing the laser on regions in a sample the reaction path can be monitored with changing temperature with a rapid scan rate.After heating lithium borohydride through its phase change and melting point, shifts in peak position and peak width were observed, which agreed with other studies4. A sample was also heated to 500°C (under 1 bar Ar) to decompose the sample. A number of intermediates and reaction products have been predicted and observed ex situ. This work shows the in situ formation of lithium dodecaborane (Li2B12H12) and amorphous boron from liquid lithium borohydride. It is therefore possible to determine at what temperatures certain intermediates and products form.

Perchlorosilanes and Perchlorocarbosilanes as Precursors to Silicon Carbide

2006 ◽  
Vol 911 ◽  
Author(s):  
Vladimir Sevastyanov ◽  
Yurij Ezhov ◽  
Roman Pavelko ◽  
Nikolaj Kuznetsov
Keyword(s):  
Thermal Decomposition ◽  
Silicon Carbide ◽  
Low Temperature ◽  
Gas Phase ◽  
Thermodynamic Modeling ◽  
Reaction System ◽  
Reaction Products ◽  
Gaseous Species ◽  
Phase Synthesis ◽  
Key Features

AbstractHomologues with the general stoichiometry a(SiCl4) : bSi : cC : d(SiC) are shown to be potential precursors for the low-temperature gas-phase synthesis of silicon carbide. Thermal decomposition of these precursors yields the chemically stable gaseous species SiCl4 and condensed Si, C, SiC, SiC+Si, or SiC+C. Thermodynamic modeling of the thermal decomposition of octachlorotrisilane, Si3Cl8, is used to analyze the key features of the thermolysis of perchlorosilanes with the general stoichiometry a(SiCl4) : bSi. The equilibrium compositions of reaction products in the Si3Cl8+CO system are determined. This reaction system enables low-temperature (400 – 1200 K) synthesis of silicon carbide.

Reactions of vibrationally excited molecules. I. The reaction of methylene with iso butene

1959 ◽  
Vol 250 (1262) ◽  
pp. 409-421 ◽  
Keyword(s):  
Double Bond ◽  
Kinetic Energy ◽  
Hydrogen Bonds ◽  
Excess Energy ◽  
Vibrationally Excited ◽  
Carbon Double Bond ◽  
Sufficient Energy ◽  
Carbon Hydrogen Bonds ◽  
Excited Molecules

The photolysis of diazomethane in the presence of iso butene has been investigated. The results obtained are explained on the basis that the methylene initially produced may be vibrationally excited, to an extent which depends on the wavelength of the radiation employed in the photolysis, and may also contain considerable kinetic energy. The methylene resets before this excess energy is lost, attacking the carbon hydrogen bonds and carbon carbon double bond in iso butene. The latter attack yields 1.1 -dimethyl cyclo Zopropane which contains sufficient energy to isomerize, and does so, unless stabilized by collision. The results obtained are compared with those published for the photolysis of keten in the presence of iso butene.

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