The Thermal Decomposition of Tertiary Butyl Chloride in the Presence of Sulphur Hexafluoride

1962 ◽  
Vol 15 (3) ◽  
pp. 437 ◽  
Author(s):  
RL Failes ◽  
VR Stimson
Keyword(s):  
Thermal Decomposition ◽  
Gas Phase ◽  
Simple Theory ◽  
Triplet States ◽  
Phase Decomposition ◽  
Butyl Chloride ◽  
Sulphur Hexafluoride ◽  
Tertiary Butyl

No acceleration of the gas-phase decomposition of tertiary butyl chloride at 284-309 �C occurs in the presence of sulphur hexafluoride. This behaviour contrasts with that of a variety of unimolecular decompositions probably occurring via triplet states where an extension of the simple theory of activation has been found necessary.

Influence of some heavy foreign gases on the thermal decomposition of di-tertiary butyl peroxide

1958 ◽  
Vol 247 (1250) ◽  
pp. 381-389 ◽  
Keyword(s):  
Thermal Decomposition ◽  
Nitrous Oxide ◽  
Pressure Range ◽  
Order Rate Constant ◽  
Chemical Effect ◽  
Sulphur Hexafluoride ◽  
Tertiary Butyl ◽  
First Order ◽  
Butyl Peroxide ◽  
Limiting Value

The first-order rate constant for the thermal decomposition of di-tertiary butyl peroxide in the pressure range 0 to 600 mm follows an equation of the form k = A 1 n /(1+ A' 1 n + A 2 n , where n is the peroxide pressure. For a given value of n additions of sulphur hexafluoride (which appears from analysis to have no chemical effect) raise k to a limiting value, k n ,∞. This value is itself a function of the peroxide pressure approximately of the form k n , ∞ = An /(1+A' n )+B. In the light of previous work on nitrous oxide and on paraffins, these results are tentatively explained in terms of a scheme in which energized molecules go reversibly to special activated states from which decomposition follows either spontaneously or when induced by collisions.

GAS-Phase Decomposition Kinetics of MOVPE Precursors in a Counterflow Jet Reactor

1992 ◽  
Vol 282 ◽  
Author(s):  
S. A. Safvi ◽  
T. J. Mountziaris
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Gas Phase ◽  
Experimental System ◽  
Operating Conditions ◽  
Tertiary Butyl ◽  
Carrier Gas ◽  
Hydride Elimination ◽  
Counterflow Jet Reactor ◽  
Stagnation Plane

ABSTRACTA new reactor for studying the purely homogeneous thermal decomposition of organometallic precursors used in the Metalorganic Vapor Phase Epitaxy (MOVPE) of semiconductors is presented. The idea is based on the use of a counterflow jet configuration with one jet being heated and the other unheated. The heated jet contains pure carrier gas (typically hydrogen or nitrogen), while the unheated jet contains vapors of an organometallic species diluted in the same carrier gas. Under appropriate operating conditions, decomposition of the organometallic species takes place near the stagnation plane where the hot jet collides with the cool jet. Since the reactions occur in the gas phase and away from hot walls, purely homogeneous kinetics can be obtained. Such a counterflow jet reactor was designed for studying the thermal decomposition of tertiary-butyl-arsine (TBA), t-C4H9AsH2, a very promising precursor for MOVPE of GaAs films. Two-dimensional finite element simulations of transport phenomena and kinetics have been used to identify optimal operating conditions. An experimental system was constructed and capillary-sampled mass spectroscopy at the stagnation plane was used to study the thermal decomposition of TBA in nitrogen at a total pressure of 252 Torr. Gas-chromatography of the effluent gas stream was employed for positive identification of the hydrocarbon byproducts. The results indicate the existence of two major decomposition routes: (1) A low activation energy pathway producing isobutane AsH, and (2) a higher activation energy, β-hydride elimination pathway producing isobutene and arsine.

The photolysis and thermal decomposition of pyruvic acid in the gas phase

1985 ◽  
Vol 63 (2) ◽  
pp. 549-554 ◽  
Author(s):  
S. Yamamoto ◽  
R. A. Back
Keyword(s):  
Thermal Decomposition ◽  
Gas Phase ◽  
Pyruvic Acid ◽  
Light Emission ◽  
Singlet State ◽  
Hydrogen Atom Transfer ◽  
Triplet States ◽  
Primary Process ◽  
Weak Absorption ◽  
Singlet And Triplet States

The photolysis of pyruvic acid vapour has been studied at wavelengths of 366, 345, and 320 nm, at a temperature of 340 K and pressures from about 1 to 10 Torr. Products observed were CO2 and CH3CHO, with the former always in excess, and a quantum yield of CO2 of 0.9 ± 0.1 at 366 nm. Light emission was also observed, and from the effect of added O2 it was concluded that emission occurred from both singlet and triplet states. It is suggested that the primary process in the photolysis is an internal hydrogen-atom transfer followed by dissociation into CO2 and CH3—C—OH, with the latter then rearranging to give CH3CHO and other products.The absorption spectrum is reported; the first system begins at about 380 nm, rising to a maximum at about 350 nm, with εmax = 10 M−1 cm−1, and is attributed to the first excited π* ← n+ singlet state. Weak absorption below 300 nm is probably due to the π* ← n− state and much stronger absorption below 220 nm to the π* ← π state.The thermal decomposition was studied briefly at temperatures from 455 to 584 K and pressures from about 0.8 to 7 Torr. Products were the same as in the photolysis, and Arrhenius parameters of log A (s−1) = 7.19 and E = 27.7 kcal/mol were obtained, based on the formation of CO2, which was apparently a simple, homogeneous unimolecular process.

Synthesis of Sic Fine Particles by Gas-Phase Reaction Under Short-Time Microgravity

1992 ◽  
Vol 286 ◽  
Author(s):  
Takeshi Okutani ◽  
Yoshinori Nakata ◽  
Masaakt Suzuki ◽  
Yves Maniette ◽  
Nobuyoshi Goto ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Heat Source ◽  
Size Distribution ◽  
Gas Phase ◽  
Fine Particles ◽  
Rapid Heating ◽  
Exothermic Reaction ◽  
Phase Reaction ◽  
Gas Phase Reaction ◽  
Short Time

ABSTRACTSiC fine particles were synthesized by the gas-phase thermal decomposition of tetramethylsilane (Si(CH3)4) in hydrogen under microgravity of 10−4G for 10 sec. Rapid heating to the temperature over 800°C which is required for thermal decomposition of Si(CH3)4) under short-time microgravity was attained using a chemical oven where the heat of exothermic reaction of combustion synthesis of Ti-A1-4B composites was used as the heat source. Monodisperse and spherical SiC fine particles were synthesized under microgravity, whereas aggregates of SiC fine particles were synthesized under 1 G gravity. The SiC particles synthesized under microgravity (150-200 nm) were bigger in size and narrower in size distribution than those under 1 G gravity (100-150 nm).

Sign in / Sign up

Export Citation Format

Share Document