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Kinetic correlations for H2 addition and elimination reaction mechanisms during silicon hydride pyrolysis

(2010) PHYSICAL CHEMISTRY CHEMICAL PHYSICS. 12(39). p.12676-12696
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Abstract
The mechanism of H-2 addition and elimination reactions in selected silicon hydrides (SixHy, x = 1-10, y = 4-20) was modeled using quantum chemical calculations, statistical thermodynamics, transition state theory and transition state group additivity. Rate coefficients for 25 H-2 addition reactions were calculated using G3//B3LYP. For nearly every reaction, the overall conversion exhibits two steps. In the addition direction, the reactants first meet to form an adduct which then converts into a saturated silicon hydride via homolytic H-H bond cleavage. Values for the single-event Arrhenius pre-exponential factor, (A) over tilde, and the activation energy, E-a, were calculated from the G3//B3LYP rate coefficients, and a group additivity scheme was developed to predict (A) over tilde and E-a. The values predicted by group additivity are more accurate than kinetic correlations currently used in the literature, which rely on representative (A) over tilde values and the Evans-Polanyi correlation. The factors that have the most pronounced effect on (A) over tilde and E-a were investigated, and stabilization of the divalent silicon atom of the unsaturated silicon hydride with electron-donating substituents was found to influence kinetic parameters considerably. The rate coefficients for H-2 addition reactions were found to correlate reasonably well with the difference in energy between the highest occupied molecular orbital of H-2 (E-HOMO) and the lowest unoccupied molecular orbital of the reactant silylene (E-LUMO).
Keywords
RATE CONSTANTS, ACTIVATION-ENERGIES, THERMAL-DECOMPOSITION, GAS-PHASE DECOMPOSITION, REACTION-RATE PREDICTION, DENSITY-FUNCTIONAL THEORY, SILENE INSERTION REACTIONS, HYDROGEN ABSTRACTION REACTIONS, CHEMICAL-VAPOR-DEPOSITION, TRANSITION-STATE THEORY

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Citation

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Chicago
Adamczyk, Andrew, Marie-Françoise Reyniers, Guy Marin, and Linda J Broadbelt. 2010. “Kinetic Correlations for H2 Addition and Elimination Reaction Mechanisms During Silicon Hydride Pyrolysis.” Physical Chemistry Chemical Physics 12 (39): 12676–12696.
APA
Adamczyk, A., Reyniers, M.-F., Marin, G., & Broadbelt, L. J. (2010). Kinetic correlations for H2 addition and elimination reaction mechanisms during silicon hydride pyrolysis. PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 12(39), 12676–12696.
Vancouver
1.
Adamczyk A, Reyniers M-F, Marin G, Broadbelt LJ. Kinetic correlations for H2 addition and elimination reaction mechanisms during silicon hydride pyrolysis. PHYSICAL CHEMISTRY CHEMICAL PHYSICS. 2010;12(39):12676–96.
MLA
Adamczyk, Andrew, Marie-Françoise Reyniers, Guy Marin, et al. “Kinetic Correlations for H2 Addition and Elimination Reaction Mechanisms During Silicon Hydride Pyrolysis.” PHYSICAL CHEMISTRY CHEMICAL PHYSICS 12.39 (2010): 12676–12696. Print.
@article{1850159,
  abstract     = {The mechanism of H-2 addition and elimination reactions in selected silicon hydrides (SixHy, x = 1-10, y = 4-20) was modeled using quantum chemical calculations, statistical thermodynamics, transition state theory and transition state group additivity. Rate coefficients for 25 H-2 addition reactions were calculated using G3//B3LYP. For nearly every reaction, the overall conversion exhibits two steps. In the addition direction, the reactants first meet to form an adduct which then converts into a saturated silicon hydride via homolytic H-H bond cleavage. Values for the single-event Arrhenius pre-exponential factor, (A) over tilde, and the activation energy, E-a, were calculated from the G3//B3LYP rate coefficients, and a group additivity scheme was developed to predict (A) over tilde and E-a. The values predicted by group additivity are more accurate than kinetic correlations currently used in the literature, which rely on representative (A) over tilde values and the Evans-Polanyi correlation. The factors that have the most pronounced effect on (A) over tilde and E-a were investigated, and stabilization of the divalent silicon atom of the unsaturated silicon hydride with electron-donating substituents was found to influence kinetic parameters considerably. The rate coefficients for H-2 addition reactions were found to correlate reasonably well with the difference in energy between the highest occupied molecular orbital of H-2 (E-HOMO) and the lowest unoccupied molecular orbital of the reactant silylene (E-LUMO).},
  author       = {Adamczyk, Andrew and Reyniers, Marie-Fran\c{c}oise and Marin, Guy and Broadbelt, Linda J},
  issn         = {1463-9076},
  journal      = {PHYSICAL CHEMISTRY CHEMICAL PHYSICS},
  keyword      = {RATE CONSTANTS,ACTIVATION-ENERGIES,THERMAL-DECOMPOSITION,GAS-PHASE DECOMPOSITION,REACTION-RATE PREDICTION,DENSITY-FUNCTIONAL THEORY,SILENE INSERTION REACTIONS,HYDROGEN ABSTRACTION REACTIONS,CHEMICAL-VAPOR-DEPOSITION,TRANSITION-STATE THEORY},
  language     = {eng},
  number       = {39},
  pages        = {12676--12696},
  title        = {Kinetic correlations for H2 addition and elimination reaction mechanisms during silicon hydride pyrolysis},
  url          = {http://dx.doi.org/10.1039/C0CP00666A},
  volume       = {12},
  year         = {2010},
}

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