Pressure dependence of the rate constants of diels-alder reactions and calculations of activation volumes

1975 ◽  
Vol 24 (12) ◽  
pp. 2563-2569
Author(s):  
B. S. �l'yanov ◽  
S. K. Shakhova ◽  
G. A. Rubtsov
Keyword(s):  
Pressure Dependence ◽  
Rate Constants ◽  
Diels Alder

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.

Computational study on the mechanisms and kinetics of the CH2CCl + O2 reaction

2020 ◽  
Vol 98 (8) ◽  
pp. 395-402
Author(s):  
Yunju Zhang ◽  
Bing He ◽  
Yuxi Sun
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Pressure Dependence ◽  
Rate Constants ◽  
Reaction Mechanisms ◽  
Energy Surface ◽  
Computational Study ◽  
Tddft Calculations ◽  
Temperature And Pressure ◽  
Kinetics Of

The potential energy surface for the CH2CCl + O2 reaction has been investigated by using the CCSD(T)/cc-pVTZ//B3LYP/6-311++G(d,p) method. Two type reaction mechanisms have been located. The H-abstraction of CH2CCl by O2 generates CHCCl + HO2 surmounting a 20.86 kcal/mol barrier. The addition between O2 and CH2CCl proceeds to an intermediate CH2CClO2 (IM1t and IM1c) without a barrier, which can further dissociate or isomerize to various products with the complicated processes. The temperature and pressure dependence rate constants for the CH2CCl + O2 reaction were computed by means of multi-channel RRKM-TST theory. Moreover, TDDFT calculations imply that IM1t, IM1c, IM2, IM4, IM5t, and IM5c will photolyze under the sunlight.

Benzannulated Isobenzofurans

1988 ◽  
Vol 41 (2) ◽  
pp. 235 ◽  
Author(s):  
John Moursounidis ◽  
Dieter Wege
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Maleic Anhydride ◽  
Aromatic Hydrocarbons ◽  
Rate Constants ◽  
Diels Alder ◽  
Furan Series ◽  
Structure Count ◽  
Polycyclic Aromatic

A number of arynes, generated by treatment of haloarenes with sodium or potassium amide in tetrahydrofuran, were trapped with furan. The resulting dihydro epoxy arenes were converted into the following annulated isobenzofuran derivatives by using reverse Diels-Alder methodology: naphtho[l,2-clfuran, phenanthro[9,10-elfuran, pyreno[l,2-elfuran, pyreno[3,4- elfuran, anthra[l,2- elfuran, phenanthro[l,2- clfuran and phenanthro[3,4- elfuran. Bimolecular rate constants for the addition of maleic anhydride to these furans were measured, and were correlated with the Herndon structure count. Addition of arynes to selected members of this furan series yielded adducts which were deoxygenated to afford polycyclic aromatic hydrocarbons.

Pyrolysis of 1-methylcyclohexene and methylenecyclohexane

1976 ◽  
Vol 29 (3) ◽  
pp. 599 ◽  
Author(s):  
JL Garnett ◽  
WD Johnson ◽  
JE Sherwood
Keyword(s):  
Rate Constants ◽  
Alder Reaction ◽  
Diels Alder ◽  
Reaction Pathways ◽  
Main Reaction ◽  
Confidence Limits ◽  
Radical Chain ◽  
First Order ◽  
Diels Alder Reaction ◽  
Ring Fission

At 495� the decomposition of both 1-methylcyclohexene and methylenecyclohexane is homogeneous and first order overall, the rate constants (with 90% confidence limits) being (6.01 � 0.40) x 10-4 and (6.53 � 0.23) x 10-4 s-1 respectively. Pressure is not a good measure of the rate of decomposition of either isomer. Toluene inhibits the decomposition of both olefins, although the effect is more marked for the exo-isomer. The two main reaction pathways for 1-methylcyclohexene are a reverse Diels-Alder reaction, giving 2-methylbuta-1,3-diene and ethene, and a radical chain dehydrogenation to give toluene and benzene. Methylenecyclohexane cannot react through a reverse Diels-Alder reaction and ring fission gives a mixture of C3 and lower hydrocarbons. Dehydrogenation to give benzene and toluene is also important. Isomerization is a much more favoured pathway for methylenecyclohexane as expected from the relative thermodynamic stabilities of the isomers.

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