The Gas Phase Photolysis of Acetone at 3130 A in the Presence of Hydrogen Bromide. A Study of the Primary Photochemical Decomposition Processes of Acetone

1966 ◽  
Vol 70 (8) ◽  
pp. 2475-2486 ◽  
Author(s):  
Carl W. Larson ◽  
H. Edward O'Neal
Keyword(s):  
Gas Phase ◽  
Hydrogen Bromide ◽  
Decomposition Processes ◽  
Photochemical Decomposition

Gas phase photochemical decomposition of 1-bromopropane

1981 ◽  
Vol 59 (12) ◽  
pp. 1827-1833 ◽  
Author(s):  
Stuart G. Bayliss ◽  
Robert L. Failes ◽  
Jacob S. Shapiro
Keyword(s):  
Activation Energy ◽  
Light Intensity ◽  
Gas Phase ◽  
Hydrogen Bromide ◽  
Bromine Atom ◽  
Incident Light ◽  
Incident Light Intensity ◽  
Allyl Radical ◽  
Photochemical Decomposition ◽  
Overall Kinetics

The gas phase photochemical decomposition of 1-bromopropane (lbp) was studied over the temperature range 374–483 K and the pressure range10–95 kPa. Within these ranges the overall kinetics are expressed by:[Formula: see text]where I0 is the incident light intensity. The principal propagation step involves the abstraction of the secondary hydrogen by a bromine atom leading to two major products: propene and hydrogen bromide. Termination involving allyl radical is postulated, a feature that sets this photolysis apart from those of ethyl and neopentyl bromides. The overall activation energy is 33.8 ± 0.8 kJ mol−1 and it leads to Arrhenius parameters for the propagation step [3] of Ea = 29.7 kJ mol−1 and log10A = 9.1 (A in dm3 mol−1 s−1).[Formula: see text]

Catalysis by hydrogen halides in the gas phase. XIX. 2,3-Dimethylbutan-2-ol and hydrogen bromide

1968 ◽  
Vol 21 (10) ◽  
pp. 2385 ◽  
Author(s):  
RL Johnson ◽  
VR Stimson
Keyword(s):  
Gas Phase ◽  
Arrhenius Equation ◽  
Hydrogen Bromide ◽  
Phase Decomposition ◽  
Hydrogen Halides ◽  
First Order

The gas-phase decomposition of 2,3-dimethylbutan-2-ol into 2,3-dimethylbut-1-ene, 2,3-dimethylbut-2-ene, and water, catalysed by hydrogen bromide at 303-400�, is described. The rate is first-order in each reactant and the Arrhenius equation k2 = 1011.88 exp(-26490/RT) sec-l ml mole-1 is followed. The olefins appear to be in their equilibrium proportions. The effects of substitutions in the alcohol at Cα and Cβ on the rate are discussed.

Radiolysis of aqueous 2,2,2-tribromoethanol solutions

1970 ◽  
Vol 48 (16) ◽  
pp. 2542-2548 ◽  
Author(s):  
V. G. Sorensen ◽  
V. M. Bhale ◽  
K. J. McCallum ◽  
R. J. Woods
Keyword(s):  
Carbon Dioxide ◽  
Dose Rate ◽  
Glycolic Acid ◽  
Hydrogen Bromide ◽  
Photochemical Decomposition ◽  
Bromide Ion ◽  
Presence And Absence ◽  
Effect Of Oxygen

Hydrogen bromide, glycolic acid, and carbon dioxide have been identified as products of the γ-radiolysis of aqueous 2,2,2-tribromoethanol solutions. The effect of oxygen, tribromoethanol concentration, and dose rate upon the yields of bromide ion and acid have been determined, and partial radiolysis mechanisms are proposed for reaction in the presence and absence of oxygen. Dibromoacetaldehyde, reported to be a product of the photochemical decomposition of tribromoethanol solutions, was not detected in the radiolysis experiments or in tribromoethanol solutions exposed to sunlight.

Chemical Stability and Reactivity of Deprotonated Oligonucleotides (DNA) in the Gas Phase: Protonation and Solvation with Hydrogen Bromide

2008 ◽  
Vol 112 (33) ◽  
pp. 10375-10381 ◽  
Author(s):  
Stefan W. Feil ◽  
Greg K. Koyanagi ◽  
Janna Anichina ◽  
Diethard K. Bohme
Keyword(s):  
Gas Phase ◽  
Chemical Stability ◽  
Hydrogen Bromide

Mechanism of the Direct Photochemical Decomposition of Thietane and its Derivatives in the Vapor Phase, in Solution, and in Glassy Matrices

1975 ◽  
Vol 53 (12) ◽  
pp. 1744-1755 ◽  
Author(s):  
David R. Dice ◽  
Ronald P. Steer
Keyword(s):  
Low Temperature ◽  
Gas Phase ◽  
Vapor Phase ◽  
Low Temperatures ◽  
Condensed Media ◽  
Photochemical Decomposition ◽  
Glassy Matrices

The direct photolyses of thietane, 3-ethyl-2-propylthietane, and 3-methylthietane in the vapor phase, in solution, and in glassy matrices at low temperatures have been examined. The effects of varying the photolysis wavelength, the temperature, the pressure and the phase of the substrate, and of adding inert thermalizers on the nature and yields of the various products have been measured. The results are interpreted in terms of initial C—S cleavage to give a 1,4-biradical which may, in the gas phase, decompose or ring close before complete equilibration of the various rotamers is achieved, or which may be thermalized in condensed media and trapped in glassy matrices at low temperature.

Catalysis by hydrogen halides in the gas phase. XVIII. Methyl formate and hydrogen bromide

1968 ◽  
Vol 21 (7) ◽  
pp. 1711
Author(s):  
DA Kairaitis ◽  
VR Stimson
Keyword(s):  
Carbon Monoxide ◽  
Gas Phase ◽  
Decomposition Product ◽  
Methyl Formate ◽  
Arrhenius Equation ◽  
Hydrogen Bromide ◽  
Radical Chain ◽  
Hydrogen Halides ◽  
Chain Decomposition ◽  
First Order

Hydrogen bromide catalyses the decomposition of methyl formate into carbon monoxide and methanol at 390-460�. The radical chain decomposition product, methane, is formed in only a small amount that is further reduced by the addition of inhibitor. The reaction is homogeneous and molecular, is first order in each reactant, and follows the Arrhenius equation: k2 = 1012.50exp(-32200/RT)sec-1 ml mole-1 It is not reversed by added methanol.

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