Unimolecular processes in vibrationally highly excited cycloheptatrienes. I. Thermal isomerization in shock waves

Astholz, D. C.; Troe, J.; Wieters, W.

doi:10.1063/1.437352

Cited by 205 publications

(114 citation statements)

References 18 publications

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“…There are two options for the treatment of rotations. The usual option is to use the convolution method developed by Astholz et al [21], which is computationally efficient and accurate for rotors with small rotational constants. The second method is to use exact counts of rotational states.…”

Section: Sums and Densities Of Statesmentioning

confidence: 99%

Multiple‐Well, multiple‐path unimolecular reaction systems. I. MultiWell computer program suite

Barker

2001

Int J of Chemical Kinetics

558

579

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Unimolecular reaction systems in which multiple isomers undergo simultaneous reactions via multiple decomposition reactions and multiple isomerization reactions are of fundamental interest in chemical kinetics. The computer program suite described here can be used to treat such coupled systems, including the effects of collisional energy transfer (weak collisions). The program suite consists of MultiWell, which solves the internal energy master equation for complex unimolecular reactions systems; DenSum, which calculates sums and densities of states by an exact-count method; MomInert, which calculates external principal moments of inertia and internal rotation reduced moments of inertia; and Thermo, which calculates equilibrium constants and other thermodynamics quantities. MultiWell utilizes a hybrid master equation approach, which performs like an energy-grained master equation at low energies and a continuum master equation in the vibrational quasicontinuum. An adaptation of Gillespie's exact stochastic method is used for the solution. The codes are designed for ease of use. Details are presented of various methods for treating weak collisions with virtually any desired collision step-size distribution and for utilizing RRKM theory for specific unimolecular rate constants.

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Section: Sums and Densities Of Statesmentioning

confidence: 99%

Multiple‐Well, multiple‐path unimolecular reaction systems. I. MultiWell computer program suite

Barker

2001

Int J of Chemical Kinetics

558

579

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“…The barrierless entrance and exit processes were treated by the CVTST approach as aforementioned. The density and sum of states for the reactants and transition states were calculated with an increment of 10 cm −1 using the modified BeyerSwinehart algorithm [19]. The exponential down model [6,20] with a step size of E down = 400 cm −1 was applied for the collisional energy transfer.…”

Section: Hno + Ch 3 Reactionmentioning

confidence: 99%

Kinetics and mechanisms for reactions of HNO with CH₃ and C₆H₅ studied by quantum‐chemical and statistical‐theory calculations

Choi

Lin

2005

Int J of Chemical Kinetics

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Kinetics and mechanisms for the reactions of HNO with CH 3 and C 6 H 5 have been investigated by ab initio molecular orbital (MO) and transition-state theory (TST) and/or Rice-Ramsperger-Kassel-Marcus/Master Equation (RRKM/ME) calculations. The G2M(RCC, MP2)//B3LYP/6-31G(d) method was employed to evaluate the energetics for construction of their potential energy surfaces and prediction of reaction rate constants. The reactions R + HNO (R = CH 3 and C 6 H 5 ) were found to proceed by two key product channels giving (1) RH + NO and (2) RNO + H, primarily by direct abstraction and indirect association/decomposition mechanisms, respectively. As both reactions initially occur barrierlessly, their rate constants were evaluated with a canonical variational approach in our TST and RRKM/ME calculations. For practical applications, the rate constants evaluated for the atmospheric-

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“…All densities and sums of states were calculated with an increment of 10 cm À1 by using the modified Beyer ± Swinehart algorithm. [27] The collisional energy transfer was obtained from the exponential down model [28] with a step size of hDEi down 400 cm…”

Section: Calculation Of Rate Constantsmentioning

confidence: 99%

Kinetics and Mechanisms for the Reactions of Phenyl Radical with Ketene and its Deuterated Isotopomer: An Experimental and Theoretical Study

Choi

Lin

2004

ChemPhysChem

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Kinetics and mechanism for the reaction of phenyl radical (C6H5) with ketene (H2C beta=C alpha=O) were studied by the cavity ring-down spectrometric (CRDS) technique and hybrid DFT and ab initio molecular orbital calculations. The C6H5 transition at 504.8 nm was used to detect the consumption of the phenyl radical in the reaction. The absolute overall rate constants measured, including those for the reaction with CD2CO, can be expressed by the Arrhenius equation k = (5.9 +/- 1.8) x 10(11) exp[-(1160 +/- 100)/T] cm3 mol-1 s-1 over a temperature range of 301-474 K. The absence of a kinetic isotope effect suggests that direct hydrogen abstraction forming benzene and ketenyl radical is kinetically less favorable, in good agreement with the results of quantum chemical calculations at the G2MS//B3LYP6-31G(d) level of theory for all accessible product channels, including the above abstraction and additions to the C alpha, C beta, and O sites. For application to combustion, the rate constants were extrapolated over the temperature range of 298-2500 K under atmospheric pressure by using the predicted transition-state parameters and the adjusted entrance reaction barriers E alpha = E beta = 1.2 kcal mol-1; they can be represented by the following expression in units of cm3 mol-1 s-1: k alpha = 6.2 x 10(19)T-23 exp[-7590/T] and k beta = 3.2 x 10(4)T2.4 exp[-246/T].

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Unimolecular processes in vibrationally highly excited cycloheptatrienes. I. Thermal isomerization in shock waves

Cited by 205 publications

References 18 publications

Multiple‐Well, multiple‐path unimolecular reaction systems. I. MultiWell computer program suite

Multiple‐Well, multiple‐path unimolecular reaction systems. I. MultiWell computer program suite

Kinetics and mechanisms for reactions of HNO with CH₃ and C₆H₅ studied by quantum‐chemical and statistical‐theory calculations

Kinetics and Mechanisms for the Reactions of Phenyl Radical with Ketene and its Deuterated Isotopomer: An Experimental and Theoretical Study

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Unimolecular processes in vibrationally highly excited cycloheptatrienes. I. Thermal isomerization in shock waves

Cited by 205 publications

References 18 publications

Multiple‐Well, multiple‐path unimolecular reaction systems. I. MultiWell computer program suite

Multiple‐Well, multiple‐path unimolecular reaction systems. I. MultiWell computer program suite

Kinetics and mechanisms for reactions of HNO with CH3 and C6H5 studied by quantum‐chemical and statistical‐theory calculations

Kinetics and Mechanisms for the Reactions of Phenyl Radical with Ketene and its Deuterated Isotopomer: An Experimental and Theoretical Study

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Kinetics and mechanisms for reactions of HNO with CH₃ and C₆H₅ studied by quantum‐chemical and statistical‐theory calculations