On the application of RRKM theory to the unimolecular isomerization of monofluorocyclopropane: a reaction with multiple fall-off characteristics?

1978 ◽  
Vol 56 (1) ◽  
pp. 29-31 ◽  
Author(s):  
Michael C. Flowers
Keyword(s):  
Pressure Dependence ◽  
Reaction Products ◽  
Arrhenius Parameters ◽  
Rrkm Theory ◽  
Product Yields ◽  
Cis And Trans

Monofluorocyclopropane isomerizes at 475 °C to form cis- and trans-1-fluoropropene, 2-fluoropropene, and 3-fluoropropene. The relative amounts of these products formed are pressure dependent. It is shown that, using the previously determined Arrhenius parameters for the formation of each product, RRKM theory does account satisfactorily for the pressure dependence of the product yields for all the reaction products.

The unimolecular isomerisation of monofluorocyclopropane: a reaction with multiple fall-off characteristics?

1977 ◽  
Vol 55 (10) ◽  
pp. 1595-1598 ◽  
Author(s):  
Mohammad H. Baghal-Vayjooee ◽  
Andrew W. Yau ◽  
Huw O. Pritchard
Keyword(s):  
Master Equation ◽  
Pressure Dependence ◽  
Product Formation ◽  
Equation Approach ◽  
Rrkm Theory ◽  
Master Equation Approach ◽  
The Difference ◽  
The Individual ◽  
Cis And Trans

Monofluorocyclopropane isomerises at 475 °C to give four products, cis-1-fluoropropene, trans-1-fluoropropene, 2-fluoropropene, and 3-fluoropropene; the ratios of product formation are not independent of pressure and it is shown that, using the Kassel representation, the individual fall-off curves correspond to values of the parameter s = 9, 6, 4, and 4 respectively. It is shown that although conventional RRKM theory can account satisfactorily for the difference in fall-off behaviour between the cis- and trans-1-propene yields, it cannot account for the pressure dependence of the formation of 2- and 3-fluoropropene; the latter behaviour is, however, easily understood in terms of the master-equation approach.

REACTION OF OXYGEN ATOMS WITH BUTADIENE

1960 ◽  
Vol 38 (11) ◽  
pp. 2187-2195 ◽  
Author(s):  
R. J. Cvetanović ◽  
L. C. Doyle
Keyword(s):  
Pressure Dependence ◽  
Rate Constants ◽  
Room Temperature ◽  
Relative Rate ◽  
Excess Energy ◽  
General Mechanism ◽  
Arrhenius Parameters ◽  
Heats Of Reaction ◽  
Relative Rate Constants ◽  
Oxygen Atoms

Reaction of oxygen atoms with 1,3-butadiene has been investigated at room temperature. It is found that it conforms to the general mechanism established previously for the analogous reactions of monoolefins. Only 1,2-addition occurs, and the addition products, butadiene monoxide and 3-butenal, possess excess energy when formed as a result of high heats of reaction. The pressure dependence of the formation of the addition products yields the values of the "lifetimes" of the initially produced "hot" molecules. The relative rate constants have been determined at 25 and 127 °C and from these the relative values of the Arrhenius parameters have been calculated.

The acid-catalysed hydrolysis of α-methylallyl acetate in aqueous solution

1968 ◽  
Vol 21 (7) ◽  
pp. 1727
Author(s):  
RA Fredlein ◽  
I Lauder
Keyword(s):  
Aqueous Solution ◽  
Reaction Products ◽  
Arrhenius Parameters ◽  
Crotyl Alcohol ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Tracer Experiments

The kinetics of the acid-catalysed hydrolysis of a-methylallyl acetate in aqueous solution have been studied over the range 30-100�. Oxygen-18 tracer experiments reveal the mechanism to be solely Aac2 and the Arrhenius parameters are consistent with this conclusion. Crotyl alcohol is observed in the reaction products. The formation of rearranged alcohol is explained by allylic isomerization of the α-methylallyl alcohol produced by the hydrolysis.

RADIATION CHEMISTRY OF CYCLOHEXANE: IV. PRIMARY PRODUCT YIELDS IN THE IRRADIATION OF CYCLOHEXANE

1961 ◽  
Vol 39 (12) ◽  
pp. 2381-2388 ◽  
Author(s):  
P. J. Dyne ◽  
J. A. Stone
Keyword(s):  
Radiation Chemistry ◽  
Secondary Reaction ◽  
Reaction Products ◽  
Primary Reaction ◽  
Product Yields ◽  
Primary Products ◽  
High Irradiation

The radiolysis of cyclohexane has been studied at low total doses and initial G values have been determined. Ninety-nine per cent of the evolved hydrogen has been accounted for in hydrogen-deficient products. Cyclohexene, bicyclohexyl, and cyclohexyl-hexene-1 have been identified as primary reaction products. Cyclohexyl-cyclohexene has been identified as a secondary reaction product. The use of high irradiation doses has been shown to lead to decreases in the initial G values of all primary products.

Pressure Dependence of Product Yields in the Direct Photolysis of Methanol Vapor at 1849°Å

1973 ◽  
Vol 51 (1) ◽  
pp. 147-148 ◽  
Author(s):  
O. Sonia Herasymowych ◽  
Arthur R. Knight
Keyword(s):  
Quantum Yield ◽  
Exposure Time ◽  
Pressure Dependence ◽  
High Pressures ◽  
Yield Enhancement ◽  
Direct Photolysis ◽  
Methanol Vapor ◽  
Product Yields

Hydrogen and methane yields from the 1849 Å photolysis of methanol vapor in an all-quartz system have been investigated as a function of exposure time and pressure of CH3OH and added CO2.Product yields are decreased by the inert addend, and by the substrate itself at high pressures, in contrast to the collision-induced quantum yield enhancement reported to be occurring in this system.

The synthesis, characterization, and thermal isomerization of some 1,1,2,2-tetraarylcyclopropanes

1982 ◽  
Vol 60 (18) ◽  
pp. 2313-2320 ◽  
Author(s):  
Donald R. Arnold ◽  
Danial D. M. Wayner ◽  
Masato Yoshida
Keyword(s):  
Transition State ◽  
Chemical Shifts ◽  
Thermal Isomerization ◽  
Spectral Characterization ◽  
Arrhenius Parameters ◽  
Cis And Trans

The synthesis and spectral characterization of an extensive series of 1,1,2,2-tetraarylcyclopropanes are reported. The effects of substituents on the 13Cmr and 1Hmr chemical shifts are examined in detail. In a series of symmetrically substituted derivatives, the, 13Cmr chemical shifts correlate with ΣσR0. This correlation is only observed in cases where the Cα—Cβ bond has no net polarity. Details of the thermal isomerization of those derivatives for which the possibility of cis and trans configurations exists are also reported. Trends in the Arrhenius parameters provide evidence for the biradical character of the transition state. Other data supporting the biradical character of the transition state are discussed.

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