Rate coefficients and product branching ratios for (E)-2-butenal + H reactions

2020 ◽  
Vol 22 (25) ◽  
pp. 14246-14254
Author(s):  
Maiara Oliveira Passos ◽  
Igor Araujo Lins ◽  
Tiago Vinicius Alves
Keyword(s):  
Rate Constants ◽  
Hydrogen Abstraction ◽  
Branching Ratios ◽  
Rate Coefficients ◽  
Variational Theory ◽  
Hydrogen Atoms ◽  
Small Curvature ◽  
Thermal Rate Constants ◽  
First Time ◽  
Product Branching

Thermal rate constants for the hydrogen abstraction reactions of (E)-2-butenal by hydrogen atoms were calculated, for the first time, using the multipath canonical variational theory with small-curvature tunneling (MP-CVT/SCT).

The Mercury-Sensitized Photolysis of Pentamethyldisilane

1996 ◽  
Vol 51 (1-2) ◽  
pp. 105-115 ◽  
Author(s):  
C. Kerst ◽  
P. Potzinger ◽  
H. Gg. Wagner
Keyword(s):  
Quantum Yield ◽  
Rate Constants ◽  
Hydrogen Abstraction ◽  
Branching Ratios ◽  
Bond Breaking ◽  
Hydrogen Atoms ◽  
Substitution Reactions ◽  
Abstraction Reaction

Abstract Two primary processes were observed in the Hg-sensitized photolysis of Me 5 Si 2 H: (I) hydrogen abstraction from the Si-H bond with a quantum yield of 0(1) = 0.85, (V) Si-Si bond breaking with 0(V) = 0.04. The hydrogen atoms formed in (/) undergo an H atom abstraction reaction (k(3)), as well as substitution reactions at the Si centers resulting in the formation of dimethylsilane and trimethylsilyl radical (k(4)) or trimethylsilane and dimethylsilyl radical (k(5)). The following branching ratios have been determined:[xxx]The ratio of disproportionation (k(2)) to combination (k(1)) for the pentamethyldisilyl radical has been determined with MeOH as the scavenger for 1-methyl-l-trimethylsilylsilene, 0.046 < k(2)/A: C1) < 0.071. A mechanism with pertinent rate constants has been proposed which accounts for theresults.

Differences in the torsional anharmonicity between reactant and transition state: the case of 3-butenal + H abstraction reactions

2021 ◽  
Author(s):  
Maiara Oliveira Passos ◽  
Igor Araujo Lins ◽  
Mateus Fernandes Venâncio ◽  
Tiago Vinicius Alves
Keyword(s):  
Hydrogen Atom ◽  
Transition State ◽  
Hydrogen Abstraction ◽  
Rate Coefficients ◽  
Variational Theory ◽  
Small Curvature

Thermal rate coefficients for the hydrogen abstraction reactions of 3-butenal by hydrogen atom were obtained applying the multipath canonical variational theory with small-curvature tunneling (MP-CVT/SCT). Torsional anharmonicity due to the...

Barrierless Reactions of Three Benzonitrile Radical Cations with Ethylene

2020 ◽  
Vol 73 (8) ◽  
pp. 705
Author(s):  
Oisin J. Shiels ◽  
P. D. Kelly ◽  
Stephen J. Blanksby ◽  
Gabriel da Silva ◽  
Adam J. Trevitt
Keyword(s):  
Ion Trap ◽  
Radical Cations ◽  
Branching Ratios ◽  
Ring Closure ◽  
Van Der Waals Complexes ◽  
Rate Coefficients ◽  
Ion Trap Mass Spectrometry ◽  
Closure Mechanism ◽  
Product Ions ◽  
Product Branching

Reactions of three protonated benzonitrile radical cations with ethylene are investigated. Product branching ratios and reaction kinetics, measured using ion-trap mass spectrometry, are reported and mechanisms are developed with support from quantum chemical calculations. Reactions proceed via pre-reactive van der Waals complexes with no energy barrier (above the reactant energy) and form radical addition and addition–elimination product ions. Rate coefficients are 4-dehydrobenzonitrilium: 1.72±0.01×10−11 cm3 molecule−1 s−1, 3-dehydrobenzonitrilium: 1.85±0.01×10−11 cm3 molecule−1 s−1, and 2-dehydrobenzonitrilium: 5.96±0.06×10−11 cm3 molecule−1 s−1 (with±50% absolute uncertainty). A ring-closure mechanism involving the protonated nitrile substituent is proposed for the 2-dehydrobenzonitrilium case and suggests favourable formation of the protonated indenimine cation.

scholarly journals Prediction of absolute rate coefficients and product branching ratios for the C(3P)+allene reaction system

2002 ◽  
Vol 117 (15) ◽  
pp. 7055-7067 ◽  
Author(s):  
Harold W. Schranz ◽  
Sean C. Smith ◽  
Alexander M. Mebel ◽  
Sheng H. Lin
Keyword(s):  
Reaction System ◽  
Branching Ratios ◽  
Rate Coefficients ◽  
Absolute Rate ◽  
Product Branching

scholarly journals Theoretical Kinetics Study Of The HO2 + C2H5OH Hydrogen Abstraction Reaction

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Nguyen Trong Nghia
Keyword(s):  
Transition State ◽  
Rate Constants ◽  
Transition State Theory ◽  
Hydrogen Abstraction ◽  
Branching Ratios ◽  
State Theory ◽  
Kinetics Study ◽  
Abstraction Reaction ◽  
Hydrogen Abstraction Reaction ◽  
Ho2 Radical

C2H5OH has been using as an alternative fuel for decades; HO2 also plays a pivotal role in the combustion. The kinetics and mechanism for the reaction between C2H5OH and HO2 radical has been investigated using the molecular parameters for the reactants, transition states and products predicted at the CCSD(T)//B3LYP/6-311++G(3df,2p) level of theory. There are ten pair products have been found including C2H5O + H2O2 (PR1), CH3CHOH + H2O2 (PR2), CH2CH2OH + H2O2 (PR3), CH3CH2OOOH + H (PR4), C2H5 + HOOOH (PR5), CH3CH2OOH + OH (PR6), CH3CH(OH)OOH + H (PR7), HOCH2CH2OH + H (PR8), HOOCH3 + CH2OH (PR9), and CH3 + HOOCH2OH (PR10) in which the second and third ones are the major channels. The rate constants and branching ratios for all H-abstraction reactions have been calculated using the conventional transition state theory with asymmetric Eckart tunneling corrections for the temperature ranging from 298 to 2000 K.

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