Ab Initio and RRKM/Master Equation Analysis of the Photolysis and Thermal Unimolecular Decomposition of Bromoacetaldehyde

2021 ◽  
Author(s):  
Ibrahim Sadiek ◽  
Gernot Friedrichs ◽  
Yasuyuki Sakai
Keyword(s):  
Ab Initio ◽  
Master Equation ◽  
Unimolecular Decomposition ◽  
Equation Analysis

scholarly journals Ab-initio studies of thermal unimolecular decomposition of furan: A complementary deterministic and stochastic master equation model

Fuel ◽  
2020 ◽  
Vol 264 ◽  
pp. 116492 ◽  
Author(s):  
Tam V.T. Mai ◽  
Yao-Yuan Chuang ◽  
Binod Raj Giri ◽  
Lam K. Huynh
Keyword(s):  
Ab Initio ◽  
Master Equation ◽  
Equation Model ◽  
Unimolecular Decomposition ◽  
Stochastic Master Equation

scholarly journals Direct Kinetic Measurements and Master Equation Modelling of the Unimolecular Decomposition of Resonantly-Stabilized CH2CHCHC(O)OCH3 Radical and an Upper Limit Determination for CH2CHCHC(O)OCH3 + O2 Reaction

2020 ◽  
Vol 234 (7-9) ◽  
pp. 1251-1268 ◽  
Author(s):  
Satya Prakash Joshi ◽  
Prasenjit Seal ◽  
Timo Theodor Pekkanen ◽  
Raimo Sakari Timonen ◽  
Arrke J. Eskola
Keyword(s):  
Master Equation ◽  
Density Functional ◽  
Rate Coefficient ◽  
Decomposition Kinetics ◽  
Basis Sets ◽  
Stationary Points ◽  
Unimolecular Decomposition ◽  
Kinetic Measurements ◽  
Point Energy ◽  
Upper Limit

AbstractMethyl-Crotonate (MC, (E)-methylbut-2-enoate, CH3CHCHC(O)OCH3) is a potential component of surrogate fuels that aim to emulate the combustion of fatty acid methyl ester (FAME) biodiesels with significant unsaturated FAME content. MC has three allylic hydrogens that can be readily abstracted under autoignition and combustion conditions to form a resonantly-stabilized CH2CHCHC(O)OCH3 radical. In this study we have utilized photoionization mass spectrometry to investigate the O2 addition kinetics and thermal unimolecular decomposition of CH2CHCHC(O)OCH3 radical. First we determined an upper limit for the bimolecular rate coefficient of CH2CHCHC(O)OCH3 + O2 reaction at 600 K (k ≤ 7.5 × 10−17 cm3 molecule−1 s−1). Such a small rate coefficient suggest this reaction is unlikely to be important under combustion conditions and subsequent efforts were directed towards measuring thermal unimolecular decomposition kinetics of CH2CHCHC(O)OCH3 radical. These measurements were performed between 750 and 869 K temperatures at low pressures (<9 Torr) using both helium and nitrogen bath gases. The potential energy surface of the unimolecular decomposition reaction was probed at density functional (MN15/cc-pVTZ) level of theory and the electronic energies of the stationary points obtained were then refined using the DLPNO-CCSD(T) method with the cc-pVTZ and cc-pVQZ basis sets. Master equation simulations were subsequently carried out using MESMER code along the kinetically important reaction pathway. The master equation model was first optimized by fitting the zero-point energy corrected reaction barriers and the collisional energy transfer parameters $\Delta{E_{{\text{down}},\;{\text{ref}}}}$ and n to the measured rate coefficients data and then utilize the constrained model to extrapolate the decomposition kinetics to higher pressures and temperatures. Both the experimental results and the MESMER simulations show that the current experiments for the thermal unimolecular decomposition of CH2CHCHC(O)OCH3 radical are in the fall-off region. The experiments did not provide definite evidence about the primary decomposition products.

Master equation lumping for multi-well potential energy surfaces: a bridge between ab initio based rate constant calculations and large kinetic mechanisms

2021 ◽  
pp. 129954
Author(s):  
Luna Pratali Maffei ◽  
Matteo Pelucchi ◽  
Carlo Cavallotti ◽  
Andrea Bertolino ◽  
Tiziano Faravelli
Keyword(s):  
Potential Energy ◽  
Ab Initio ◽  
Master Equation ◽  
Rate Constant ◽  
Potential Energy Surfaces ◽  
Kinetic Mechanisms ◽  
Energy Surfaces

scholarly journals Time-Resolved Measurements and Master Equation Modelling of the Unimolecular Decomposition of CH3OCH2

2020 ◽  
Vol 234 (7-9) ◽  
pp. 1233-1250 ◽  
Author(s):  
Arrke J. Eskola ◽  
Mark A. Blitz ◽  
Michael J. Pilling ◽  
Paul W. Seakins ◽  
Robin J. Shannon
Keyword(s):  
Energy Transfer ◽  
Master Equation ◽  
Rate Coefficient ◽  
Zero Point ◽  
Buffer Gas ◽  
Unimolecular Decomposition ◽  
Time Resolved ◽  
Point Energy ◽  
Wide Range ◽  
Transfer Parameters

AbstractThe rate coefficient for the unimolecular decomposition of CH3OCH2, k1, has been measured in time-resolved experiments by monitoring the HCHO product. CH3OCH2 was rapidly and cleanly generated by 248 nm excimer photolysis of oxalyl chloride, (ClCO)2, in an excess of CH3OCH3, and an excimer pumped dye laser tuned to 353.16 nm was used to probe HCHO via laser induced fluorescence. k1(T,p) was measured over the ranges: 573–673 K and 0.1–4.3 × 1018 molecule cm−3 with a helium bath gas. In addition, some experiments were carried out with nitrogen as the bath gas. Ab initio calculations on CH3OCH2 decomposition were carried out and a transition-state for decomposition to CH3 and H2CO was identified. This information was used in a master equation rate calculation, using the MESMER code, where the zero-point-energy corrected barrier to reaction, ΔE0,1, and the energy transfer parameters, ⟨ΔEdown⟩ × Tn, were the adjusted parameters to best fit the experimental data, with helium as the buffer gas. The data were combined with earlier measurements by Loucks and Laidler (Can J. Chem.1967, 45, 2767), with dimethyl ether as the third body, reinterpreted using current literature for the rate coefficient for recombination of CH3OCH2. This analysis returned ΔE0,1 = (112.3 ± 0.6) kJ mol−1, and leads to $k_{1}^{\infty}(T)=2.9\times{10^{12}}$ (T/300)2.5 exp(−106.8 kJ mol−1/RT). Using this model, limited experiments with nitrogen as the bath gas allowed N2 energy transfer parameters to be identified and then further MESMER simulations were carried out, where N2 was the buffer gas, to generate k1(T,p) over a wide range of conditions: 300–1000 K and N2 = 1012–1025 molecule cm−3. The resulting k1(T,p) has been parameterized using a Troe-expression, so that they can be readily be incorporated into combustion models. In addition, k1(T,p) has been parametrized using PLOG for the buffer gases, He, CH3OCH3 and N2.

scholarly journals Diffusion of small clusters on metal (100) surfaces: Exact master-equation analysis for lattice-gas models

1999 ◽  
Vol 59 (4) ◽  
pp. 3224-3233 ◽  
Author(s):  
J. R. Sanchez ◽  
J. W. Evans
Keyword(s):  
Master Equation ◽  
Lattice Gas ◽  
Equation Analysis ◽  
Lattice Gas Models ◽  
Small Clusters

Boltzmann master equation analysis of preequilibrium neutron emission from heavy-ion collisions at 35 MeV/nucleon

1988 ◽  
Vol 38 (4) ◽  
pp. 1746-1756 ◽  
Author(s):  
B. A. Remington ◽  
M. Blann ◽  
A. Galonsky ◽  
L. Heilbronn ◽  
F. Deak ◽  
...  
Keyword(s):  
Master Equation ◽  
Heavy Ion Collisions ◽  
Neutron Emission ◽  
Heavy Ion ◽  
Ion Collisions ◽  
Equation Analysis

Unimolecular decomposition of chemically activated triplet C4HD3 complexes: A combined crossed-beam and ab initio study

2001 ◽  
Vol 115 (11) ◽  
pp. 5117-5125 ◽  
Author(s):  
R. I. Kaiser ◽  
A. M. Mebel ◽  
Y. T. Lee ◽  
A. H. H. Chang
Keyword(s):  
Ab Initio ◽  
Ab Initio Study ◽  
Unimolecular Decomposition

Reduced master equation analysis of multiple–tunnel junction single-electron memory device

2000 ◽  
Vol 88 (2) ◽  
pp. 869-877 ◽  
Author(s):  
M. B. A. Jalil ◽  
M. Wagner
Keyword(s):  
Master Equation ◽  
Tunnel Junction ◽  
Memory Device ◽  
Single Electron ◽  
Equation Analysis

State-resolved master equation analysis of thermochemical nonequilibrium of nitrogen

2013 ◽  
Vol 415 ◽  
pp. 237-246 ◽  
Author(s):  
Jae Gang Kim ◽  
Iain D. Boyd
Keyword(s):  
Master Equation ◽  
Equation Analysis
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