Theoretical Study on the Reaction Path and Variational Rate Constant of the Reaction HNCO + NH → NCO + NH2

1998 ◽  
Vol 102 (7) ◽  
pp. 1194-1199 ◽  
Author(s):  
Zhen-Feng Xu ◽  
Jia-Zhong Sun
Keyword(s):  
Rate Constant ◽  
Theoretical Study ◽  
Reaction Path

Regeneration Mechanism Studied by Potential-Time Response to Sinusoidal Current-Time Function

1997 ◽  
Vol 62 (10) ◽  
pp. 1511-1526
Author(s):  
María-Luisa Alcaraz ◽  
Ángela Molina
Keyword(s):  
Kinetic Parameters ◽  
Rate Constant ◽  
Theoretical Study ◽  
Time Function ◽  
Time Response ◽  
Current Time ◽  
Regeneration Mechanism ◽  
Sinusoidal Current ◽  
Regeneration Processes

A theoretical study of the potential-time response to sinusoidal current applied to static and dynamic electrodes for regeneration processes is presented. Methods for determination of the regeneration fraction, rate constant of the chemical reaction and heterogeneous kinetic parameters are proposed.

scholarly journals Theoretical Study of Thermal Cracking For Acenaphthylene Molecule

2013 ◽  
Vol 10 (3) ◽  
pp. 1071-1081
Author(s):  
Baghdad Science Journal
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Reaction Path ◽  
Polyaromatic Hydrocarbons ◽  
Thermal Cracking ◽  
Triplet States ◽  
Bond Energies ◽  
Functional Theory ◽  
Repulsion Energy ◽  
Bond Breakage

Density Functional Theory (DFT) calculations were carried out to study the thermal cracking for acenaphthylene molecule to estimate the bond energies for breaking C8b-C5a , C5a-C5 , C5-C4 , and C5-H5 bonds as well as the activation energies. It was found that for C8b-C5a , C5-C4 , and C5-H5 reactions it is often possible to identify one pathway for bond breakage through the singlet or triplet states. The atomic charges , dipole moment and nuclear – nuclear repulsion energy supported the breakage bond .Also, it was found that the activation energy value for C5-H5 bond breakage is lower than that required for C8b-C5a , C5a-C5 , C5-C4 bonds which refer to C5-H5 bond in acenaphthylene molecule are weaker than C8b-C5a , C5a-C5 , C5-C4 bonds .It is reasonable to presume that C5-H5 bonds are broken first when a acenaphthylene molecule is exposed to thermal cracking. It seems that the characteristic planarity for the polyaromatic hydrocarbons is an important factor to acquire the molecule structure of the required stability along the reaction path . The trends in the bond energies and the configuration structures are discussed .

scholarly journals Theoretical Study of the Iron Complexes with Lipoic and Dihydrolipoic Acids: Exploring Secondary Antioxidant Activity

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 674
Author(s):  
Roger Monreal-Corona ◽  
Jesse Biddlecombe ◽  
Angela Ippolito ◽  
Nelaine Mora-Diez
Keyword(s):  
Antioxidant Activity ◽  
Electron Transfer ◽  
Rate Constant ◽  
Thermodynamic Stability ◽  
Rate Constants ◽  
Theoretical Study ◽  
Oh Radicals ◽  
Single Electron Transfer ◽  
Coordination Numbers ◽  
Ph Conditions

The thermodynamic stability of twenty-nine Fe(III) complexes with various deprotonated forms of lipoic (LA) and dihydrolipoic (DHLA) acids, with coordination numbers 4, 5 and 6, is studied at the M06(SMD)/6-31++G(d,p) level of theory in water under physiological pH conditions at 298.15 K. Even though the complexes with LA- are more stable than those with DHLA−, the most thermodynamically stable Fe(III) complexes involve DHLA2−. The twenty-four exergonic complexes are used to evaluate the secondary antioxidant activity of DHLA and LA relative to the Fe(III)/Fe(II) reduction by O2•− and ascorbate. Rate constants for the single-electron transfer (SET) reactions are calculated. The thermodynamic stability of the Fe(III) complexes does not fully correlate with the rate constant of their SET reactions, but more exergonic complexes usually exhibit smaller SET rate constants. Some Cu(II) complexes and their reduction to Cu(I) are also studied at the same level of theory for comparison. The Fe(III) complexes appear to be more stable than their Cu(II) counterparts. Relative to the Fe(III)/Fe(II) reduction with ascorbate, DHLA can fully inhibit the formation of •OH radicals, but not by reaction with O2•−. Relative to the Cu(II)/Cu(I) reduction with ascorbate, the effects of DHLA are moderate/high, and with O2•− they are minor. LA has minor to negligible inhibition effects in all the cases considered.

Theoretical study on the insertion reaction of CH(X2Π) with CH4

1997 ◽  
Vol 75 (7) ◽  
pp. 996-1001 ◽  
Author(s):  
Zhi-Xiang Wang ◽  
Ming-Bao Huang. ◽  
Ruo-Zhuang Liu
Keyword(s):  
Electron Correlation ◽  
Energy Surface ◽  
Theoretical Study ◽  
Reaction Path ◽  
Basis Sets ◽  
Insertion Reaction ◽  
Molecular Orbital Calculations ◽  
Insertion Reactions ◽  
Moller Plesset ◽  
Ch Radical

The CH + CH4 reaction has been studied by means of ab initio molecular orbital calculations incorporating electron correlation with Møller–Plesset perturbation theory up to second and fourth orders with the 6-31G(d,p) and 6-311++G(2d,p) basis sets. An energetically feasible insertion reaction path has been found in the potential energy surface that confirms the experimental proposal for the mechanism of the CH + CH4 reaction. The feature of the mechanism for the CH + CH4 insertion reaction is found to be different from the feature of the mechanisms for the CH + NH3, CH + H2O, and CH + HF insertion reactions, but somewhat similar to that for the CH2 + CH4 insertion reaction. Energetic results for the CH + CH4 reactions are in agreement with experiment. Keywords: CH radical, methane, reaction mechanism.

A theoretical study of the influence of BF3 on the reaction path of the [4+2] cycloaddition of vinylketene with formaldimine

Tetrahedron ◽  
2007 ◽  
Vol 63 (47) ◽  
pp. 11617-11621 ◽  
Author(s):  
Angeles Peña-Gallego ◽  
Jesús Rodríguez-Otero ◽  
Enrique M. Cabaleiro-Lago
Keyword(s):  
Theoretical Study ◽  
Reaction Path

Theoretical study of dynamical properties on reaction path in molecular internal coordinates

1999 ◽  
Vol 42 (6) ◽  
pp. 605-611 ◽  
Author(s):  
Zonghe Li ◽  
Hong Xu ◽  
Xianzhong Xu ◽  
Xiaoyan Cao ◽  
Ruozhuang Liu
Keyword(s):  
Theoretical Study ◽  
Reaction Path ◽  
Internal Coordinates ◽  
Dynamical Properties

A theoretical study on the kinetics for ethanol reaction with formyl radical

2021 ◽  
Vol 11 (1) ◽  
pp. 38-43
Author(s):  
Nguyen Trong Nghia ◽  
Nguyen Duc Trung ◽  
Tran Thi Thoa ◽  
Phan Thi Thuy
Keyword(s):  
Free Radical ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Rate Constant ◽  
Energy Surface ◽  
Theoretical Study ◽  
Single Point ◽  
Renewable Fuels ◽  
Potential Energy Surface Calculation ◽  
Surface Calculation

C2H5OH is one of important renewable fuels. The mechanism for the C2H5OH + HCO reaction has been investigated by a potential energy surface calculation at the B3LYP/aug-cc-pVTZ (optimization) and CCSD(T)/cc-pVTZ (single-point) levels. Our results show that the HCO free radical can abstract the H atoms in the OH group giving CH3CH2O + CH2O or in the CH2 group giving CH3CHOH + CH2O. The rate constant results by TST calculations considering tunneling corrections show that the second pathway is dominate in all the calculation temperature range of 300-2000K.

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