Organic photochemistry. 71. Reaction path analysis of hydrogen abstraction by the formaldehyde triplet state

1987 ◽  
Vol 109 (11) ◽  
pp. 3231-3233 ◽  
Author(s):  
Daniel Severance ◽  
Bipin Pandey ◽  
Harry Morrison
Keyword(s):  
Triplet State ◽  
Path Analysis ◽  
Reaction Path ◽  
Hydrogen Abstraction ◽  
Organic Photochemistry

Reaction path analysis of the rate of unimolecular isomerization

1993 ◽  
Vol 99 (12) ◽  
pp. 9585-9590 ◽  
Author(s):  
Soonmin Jang ◽  
Stuart A. Rice
Keyword(s):  
Path Analysis ◽  
Reaction Path

Dual-level direct dynamics study on the hydrogen abstraction reaction of fluorine atom with 1,1-difluoro-1-chloroethane

2011 ◽  
Vol 89 (11) ◽  
pp. 1396-1402 ◽  
Author(s):  
Li Wang ◽  
Song Liu ◽  
Hongqing He ◽  
Jinglai Zhang
Keyword(s):  
Reaction Path ◽  
Hydrogen Abstraction ◽  
Single Point ◽  
Minimum Energy ◽  
State Theory ◽  
Stationary Points ◽  
Kinetic Properties ◽  
Direct Dynamics ◽  
Wide Range ◽  
Major Reaction

The kinetic properties of the reaction of F atoms with CH2H′CF2Cl are investigated by a dual-level direct dynamics method. Optimized geometries and frequencies of all the stationary points and extra points along the minimum-energy path (MEP) are obtained at the MPW1K/6–311+G(d,p) level of theory. Two complexes with energy less than that of the reactants are located in the two reactant paths, respectively. The energy profiles of two reactions are refined with the interpolated single-point energies (ISPE) method at the G3(MP2)/MPW1K level. The rate constants are evaluated using the canonical variational transition state theory (CVT) with a small-curvature tunneling correction (SCT) over a wide range of temperature 200–2000 K. Agreement between the calculated CVT/SCT rate constant and the experimental value is good at 295 K. Our calculations show that the reaction path CH2H′CF2Cl + F → CH2CF2Cl + H′F (Ra) is the major reaction path below 400 K. Moreover, the contribution of CH2H′CF2Cl + F → CHH′CF2Cl + HF (Rb) to the whole reaction increases with the temperature increasing and exceeds path Ra to be the major reaction path.

The Mechanism Analysis of O Radical Effect on Ignition of Methane/Air Mixture

2013 ◽  
Vol 437 ◽  
pp. 253-256
Author(s):  
Yong Li ◽  
Huai Rong Shen
Keyword(s):  
Sensitivity Analysis ◽  
Path Analysis ◽  
Physical Mechanism ◽  
Reaction Path ◽  
Ignition Time ◽  
Numerical Results ◽  
Mechanism Analysis

In order to show the physical mechanism of O radical on ignition of methane/air mixture, based on GRI-Mech3.0, the ignition were carried on by solving the mode of the closed reactors. It was found that the influence law on O radical effect on ignition of methane/air mixture. The numerical results indicate that the ignition time reduced about 94.7% by adding radicals of the 0.5% O. By using reaction path analysis and sensitivity analysis, the results have disciplinarian on the detailed kinetic enhancements of radicals on O radical on ignition of methane/air.

Study of Chemically Induced Dynamic Nuclear Polarization of Aliphatic Aldehydes in D2O and other Solvents

1975 ◽  
Vol 53 (17) ◽  
pp. 2548-2557 ◽  
Author(s):  
Holger E. Chen ◽  
Michael Cocivera ◽  
Shiv P. Vaish
Keyword(s):  
Triplet State ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Hydrogen Abstraction ◽  
The Other ◽  
Excited Triplet State ◽  
Relative Importance ◽  
Aliphatic Aldehydes ◽  
Excited Triplet ◽  
Chemically Induced

The chemically induced dynamic nuclear polarization arising from irradiation of aliphatic aldehydes in D2O and various other solvents is reported. The aldehydes included acetaldehyde, propionaldehyde, isobutyraldehyde, and pivalaldehyde, and the solvents were benzene, acetonitrile, cyclohexane, methylcyclohexane, perfluoromethylcyclohexane, D2O, and D2O/acetonitrile. For propionaldehyde, the variation of c.i.d.n.p. with solvent can be explained by a variation of the relative importance of α-cleavage vs. hydrogen abstraction which occur via an excited triplet state. In addition, when D2O is the solvent, the c.i.d.n.p. provides information about secondary radical reactions not observed in the other solvents. For the other aldehydes, the nature of the solvent does not seem to affect the relative importance of α-cleavage vs. hydrogen abstraction. Acetaldehyde undergoes hydrogen abstraction whereas isobutyraldehyde and pivalaldehyde undgero α-cleavage via an excited triplet state.

Sign in / Sign up

Export Citation Format

Share Document