51
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Bourgalais J, Roussel V, Capron M, Benidar A, Jasper AW, Klippenstein SJ, Biennier L, Le Picard SD. Low Temperature Kinetics of the First Steps of Water Cluster Formation. PHYSICAL REVIEW LETTERS 2016; 116:113401. [PMID: 27035301 DOI: 10.1103/physrevlett.116.113401] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Indexed: 06/05/2023]
Abstract
We present a combined experimental and theoretical low temperature kinetic study of water cluster formation. Water cluster growth takes place in low temperature (23-69 K) supersonic flows. The observed kinetics of formation of water clusters are reproduced with a kinetic model based on theoretical predictions for the first steps of clusterization. The temperature- and pressure-dependent association and dissociation rate coefficients are predicted with an ab initio transition state theory based master equation approach over a wide range of temperatures (20-100 K) and pressures (10^{-6}-10 bar).
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52
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Miller JA, Klippenstein SJ, Robertson SH, Pilling MJ, Shannon R, Zádor J, Jasper AW, Goldsmith CF, Burke MP. Comment on “When Rate Constants Are Not Enough”. J Phys Chem A 2016; 120:306-12. [DOI: 10.1021/acs.jpca.5b06025] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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53
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Labbe NJ, Sivaramakrishnan R, Goldsmith CF, Georgievskii Y, Miller JA, Klippenstein SJ. Weakly Bound Free Radicals in Combustion: "Prompt" Dissociation of Formyl Radicals and Its Effect on Laminar Flame Speeds. J Phys Chem Lett 2016; 7:85-89. [PMID: 26655248 DOI: 10.1021/acs.jpclett.5b02418] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Weakly bound free radicals have low-dissociation thresholds such that at high temperatures, time scales for dissociation and collisional relaxation become comparable, leading to significant dissociation during the vibrational-rotational relaxation process. Here we characterize this "prompt" dissociation of formyl (HCO), an important combustion radical, using direct dynamics calculations for OH + CH2O and H + CH2O (key HCO-forming reactions). For all other HCO-forming reactions, presumption of a thermal incipient HCO distribution was used to derive prompt dissociation fractions. Inclusion of these theoretically derived HCO prompt dissociation fractions into combustion kinetics models provides an additional source for H-atoms that feeds chain-branching reactions. Simulations using these updated combustion models are therefore shown to enhance flame propagation in 1,3,5-trioxane and acetylene. The present results suggest that HCO prompt dissociation should be included when simulating flames of hydrocarbons and oxygenated molecules and that prompt dissociations of other weakly bound radicals may also impact combustion simulations.
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54
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Sleiman C, González S, Klippenstein SJ, Talbi D, El Dib G, Canosa A. Pressure dependent low temperature kinetics for CN + CH3CN: competition between chemical reaction and van der Waals complex formation. Phys Chem Chem Phys 2016; 18:15118-32. [DOI: 10.1039/c6cp01982j] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The gas phase reaction between the CN radical and acetonitrile CH3CN was investigated experimentally with a CRESU apparatus and a slow flow reactor as well as theoretically to explore the temperature and pressure dependence of its rate coefficient from 354 K down to 23 K.
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55
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Mebel AM, Georgievskii Y, Jasper AW, Klippenstein SJ. Pressure-dependent rate constants for PAH growth: formation of indene and its conversion to naphthalene. Faraday Discuss 2016; 195:637-670. [DOI: 10.1039/c6fd00111d] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unraveling the mechanisms for growth of polycyclic aromatic hydrocarbons (PAHs) requires accurate temperature- and pressure-dependent rate coefficients for a great variety of feasible pathways. Even the pathways for the formation of the simplest PAHs, indene and naphthalene, are fairly complex. These pathways provide important prototypes for modeling larger PAH growth. In this work we employ the ab initio RRKM theory-based master equation approach to predict the rate constants involved in the formation of indene and its conversion to naphthalene. The reactions eventually leading to indene involve C9Hx (x = 8–11) potential energy surfaces (PESs) and include C6H5 + C3H4 (allene and propyne), C6H6 + C3H3, benzyl + C2H2, C6H5 + C3H6, C6H6 + C3H5 and C6H5 + C3H5. These predictions allow us to make a number of valuable observations on the role of various mechanisms. For instance, we demonstrate that reactions which can significantly contribute to the formation of indene include phenyl + allene and H-assisted isomerization to indene of its major product, 3-phenylpropyne, benzyl + acetylene, and the reactions of the phenyl radical with propene and the allyl radical, both proceeding via the 3-phenylpropene intermediate. 3-Phenylpropene can be activated to a 1-phenylallyl radical, which in turn rapidly decomposes to indene. Next, indene can be converted to benzofulvene or naphthalene under typical combustion conditions, via its activation by H atom abstraction and methyl substitution on the five-membered ring followed by isomerization and decomposition of the resulting 1-methylindenyl radical, C10H9 → C10H8 + H. Alternatively, the same region of the C10H9 PES can be accessed through the reaction of benzyl with propargyl, C7H7 + C3H3 → C10H10 → C10H9 + H, which therefore can also contribute to the formation of benzofulvene or naphthalene. Benzofulvene easily transforms to naphthalene by H-assisted isomerization. An analysis of the effect of pressure on the reaction outcome and relative product yields is given, and modified Arrhenius fits of the rate constants are reported for the majority of the considered reactions. Ultimately, the implementation of such expressions in detailed kinetic models will help quantify the role of these reactions for PAH growth in various environments.
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56
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Harding LB, Klippenstein SJ. Comment on “A novel and facile decay path of Criegee intermediates by intramolecular insertion reactions via roaming transition states” [J. Chem. Phys. 142, 124312 (2015)]. J Chem Phys 2015; 143:167101. [DOI: 10.1063/1.4934801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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57
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Louie MK, Francisco JS, Verdicchio M, Klippenstein SJ, Sinha A. Dimethylamine Addition to Formaldehyde Catalyzed by a Single Water Molecule: A Facile Route for Atmospheric Carbinolamine Formation and Potential Promoter of Aerosol Growth. J Phys Chem A 2015; 120:1358-68. [DOI: 10.1021/acs.jpca.5b04887] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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58
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Klippenstein SJ, Pratt ST. A Tribute to Lawrence B. Harding, Joe V. Michael, and Albert F. Wagner for Their 100 Years of Combustion Kinetics Studies at Argonne. J Phys Chem A 2015; 119:7075-7. [DOI: 10.1021/acs.jpca.5b01917] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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59
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Burke MP, Goldsmith CF, Klippenstein SJ, Welz O, Huang H, Antonov IO, Savee JD, Osborn DL, Zádor J, Taatjes CA, Sheps L. Multiscale Informatics for Low-Temperature Propane Oxidation: Further Complexities in Studies of Complex Reactions. J Phys Chem A 2015; 119:7095-115. [DOI: 10.1021/acs.jpca.5b01003] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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60
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Goldsmith CF, Harding LB, Georgievskii Y, Miller JA, Klippenstein SJ. Temperature and Pressure-Dependent Rate Coefficients for the Reaction of Vinyl Radical with Molecular Oxygen. J Phys Chem A 2015; 119:7766-79. [DOI: 10.1021/acs.jpca.5b01088] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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61
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Welz O, Burke MP, Antonov IO, Goldsmith CF, Savee JD, Osborn DL, Taatjes CA, Klippenstein SJ, Sheps L. New Insights into Low-Temperature Oxidation of Propane from Synchrotron Photoionization Mass Spectrometry and Multiscale Informatics Modeling. J Phys Chem A 2015; 119:7116-29. [DOI: 10.1021/acs.jpca.5b01008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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62
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Abstract
Due to the prominent role of the propargyl radical for hydrocarbon growth within combustion environments, it is important to understand the kinetics of its formation and loss. The ab initio transition state theory-based master equation method is used to obtain theoretical kinetic predictions for the temperature and pressure dependence of the thermal decomposition of propargyl, which may be its primary loss channel under some conditions. The potential energy surface for the decomposition of propargyl is first mapped at a high level of theory with a combination of coupled cluster and multireference perturbation calculations. Variational transition state theory is then used to predict the microcanonical rate coefficients, which are subsequently implemented within the multiple-well multiple-channel master equation. A variety of energy transfer parameters are considered, and the sensitivity of the thermal rate predictions to these parameters is explored. The predictions for the thermal decomposition rate coefficient are found to be in good agreement with the limited experimental data. Modified Arrhenius representations of the rate constants are reported for utility in combustion modeling.
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63
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Sivaramakrishnan R, Michael JV, Harding LB, Klippenstein SJ. Resolving Some Paradoxes in the Thermal Decomposition Mechanism of Acetaldehyde. J Phys Chem A 2015; 119:7724-33. [DOI: 10.1021/acs.jpca.5b01032] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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64
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Annesley CJ, Randazzo JB, Klippenstein SJ, Harding LB, Jasper AW, Georgievskii Y, Ruscic B, Tranter RS. Thermal Dissociation and Roaming Isomerization of Nitromethane: Experiment and Theory. J Phys Chem A 2015; 119:7872-93. [DOI: 10.1021/acs.jpca.5b01563] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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65
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Louie MK, Francisco JS, Verdicchio M, Klippenstein SJ, Sinha A. Hydrolysis of Ketene Catalyzed by Formic Acid: Modification of Reaction Mechanism, Energetics, and Kinetics with Organic Acid Catalysis. J Phys Chem A 2015; 119:4347-57. [DOI: 10.1021/jp5076725] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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66
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Karwat DMA, Wooldridge MS, Klippenstein SJ, Davis MJ. Effects of new Ab initio rate coefficients on predictions of species formed during n-butanol ignition and pyrolysis. J Phys Chem A 2015; 119:543-51. [PMID: 25560388 DOI: 10.1021/jp509279d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Experimental, time-resolved species profiles provide critical tests in developing accurate combustion models for biofuels such as n-butanol. A number of such species profiles measured by Karwat et al. [ Karwat, D. M. A.; et al. J. Phys. Chem. A 2011 , 115 , 4909 ] were discordant with predictions from a well-tested chemical kinetic mechanism developed by Black et al. [ Black, G.; et al. Combust. Flame 2010 , 157 , 363 ]. Since then, significant theoretical and experimental efforts have focused on determining the rate coefficients of primary n-butanol consumption pathways in combustion environments, including H atom abstraction reactions from n-butanol by key radicals such as HO2 and OH, as well as the decomposition of the radicals formed by these H atom abstractions. These reactions not only determine the overall reactivity of n-butanol, but also significantly affect the concentrations of intermediate species formed during n-butanol ignition. In this paper we explore the effect of incorporating new ab initio predictions into the Black et al. mechanism on predictions of ignition delay time and species time histories for the experimental conditions studied by Karwat et al. The revised predictions for the intermediate species time histories are in much improved agreement with the measurements, but some discrepancies persist. A rate of production analysis comparing the effects of various modifications to the Black et al. mechanism shows significant changes in the predicted consumption pathways of n-butanol, and of the hydroxybutyl and butoxy radicals formed by H atom abstraction from n-butanol. The predictions from the newly revised mechanism are in very good agreement with the low-pressure n-butanol pyrolysis product species measurements of Stranic et al. [ Stranic, I.; et al. Combust. Flame 2012 , 159 , 3242 ] for all but one species. Importantly, the changes to the Black et al. mechanism show that concentrations of small products from n-butanol pyrolysis are sensitive to different reactions than those presented by Stranic et al.
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67
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Nurkowski D, Klippenstein SJ, Georgievskii Y, Verdicchio M, Jasper AW, Akroyd J, Mosbach S, Kraft M. Ab initio Variational Transition State Theory and Master Equation Study of the Reaction (OH)3SiOCH2 + CH3 ⇌ (OH)3SiOC2H5. Z PHYS CHEM 2015. [DOI: 10.1515/zpch-2014-0640] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In this paper we use variable reaction coordinate variational
transition state theory (VRC-TST) to calculate the reaction
rate constants for the two reactions, R1:
(OH)3SiOCH2 + CH3 ⇌ (OH)3SiOC2H5,
and R2:
CH2OH + CH3 ⇌ C2H5OH. The
first reaction is an important channel during the thermal
decomposition of tetraethoxysilane (TEOS), and its rate
coefficient is the main focus of this work. The second
reaction is analogous to the first and is used as a basis for
comparison. The interaction energies are obtained on-the-fly
at the CASPT2(2e,2o)/cc-pVDZ level of
theory. A one-dimensional correction to the sampled energies
was introduced to account for the energetic effects of
geometry relaxation along the reaction path. The computed,
high-pressure rate coefficients were calculated to be, R1:
k
1 = 2.406 × 10−10
T
−0.301 exp (− 271.4/T) cm3 molecule
–1 s
–1
and R2:
k
2 = 1.316 × 10−10
T
−0.189 exp (− 256.5/T) cm3 molecule
–1 s
–1. These
rates differ from each other by only 10% – 30%
over the temperature range
300–2000 K. A comparison of the computed rates
with experimental data shows good agreement and an improvement
over previous results. The pressure dependency of the reaction
R1 is explored by solving a master equation using helium as
a bath gas. The results obtained show that the reaction is
only weakly pressure dependent over the temperature range
300–1700 K, with the predicted rate constant
being within 50% of its high-pressure limit at
atmospheric pressure.
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68
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Jasper AW, Pelzer KM, Miller JA, Kamarchik E, Harding LB, Klippenstein SJ. Predictive a priori pressure-dependent kinetics. Science 2014; 346:1212-5. [DOI: 10.1126/science.1260856] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The ability to predict the pressure dependence of chemical reaction rates would be a great boon to kinetic modeling of processes such as combustion and atmospheric chemistry. This pressure dependence is intimately related to the rate of collision-induced transitions in energy E and angular momentum J. We present a scheme for predicting this pressure dependence based on coupling trajectory-based determinations of moments of the E,J-resolved collisional transfer rates with the two-dimensional master equation. This completely a priori procedure provides a means for proceeding beyond the empiricism of prior work. The requisite microcanonical dissociation rates are obtained from ab initio transition state theory. Predictions for the CH4 = CH3 + H and C2H3 = C2H2 + H reaction systems are in excellent agreement with experiment.
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69
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Jasper AW, Kamarchik E, Miller JA, Klippenstein SJ. First-principles binary diffusion coefficients for H, H2, and four normal alkanes + N2. J Chem Phys 2014; 141:124313. [DOI: 10.1063/1.4896368] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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70
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Klippenstein SJ, Pande VS, Truhlar DG. Chemical Kinetics and Mechanisms of Complex Systems: A Perspective on Recent Theoretical Advances. J Am Chem Soc 2014; 136:528-46. [DOI: 10.1021/ja408723a] [Citation(s) in RCA: 187] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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71
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Zhang P, Klippenstein SJ, Harding LB, Sun H, Law CK. Secondary channels in the thermal decomposition of monomethylhydrazine (CH3NHNH2). RSC Adv 2014. [DOI: 10.1039/c4ra13131b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The possible role of molecular decomposition channels in MMH is explored through additional investigations on triplet channels, roaming radical channels, and previously unexplored pathways on the potential energy surface.
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72
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Jasper AW, Miller JA, Klippenstein SJ. Collision Efficiency of Water in the Unimolecular Reaction CH4 (+H2O) ⇆ CH3 + H (+H2O): One-Dimensional and Two-Dimensional Solutions of the Low-Pressure-Limit Master Equation. J Phys Chem A 2013; 117:12243-55. [DOI: 10.1021/jp409086w] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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73
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Polino D, Klippenstein SJ, Harding LB, Georgievskii Y. Predictive Theory for the Addition and Insertion Kinetics of 1CH2 Reacting with Unsaturated Hydrocarbons. J Phys Chem A 2013; 117:12677-92. [DOI: 10.1021/jp406246y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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74
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Cheikh Sid Ely S, Morales SB, Guillemin JC, Klippenstein SJ, Sims IR. Low Temperature Rate Coefficients for the Reaction CN + HC3N. J Phys Chem A 2013; 117:12155-64. [DOI: 10.1021/jp406842q] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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75
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Georgievskii Y, Miller JA, Burke MP, Klippenstein SJ. Reformulation and Solution of the Master Equation for Multiple-Well Chemical Reactions. J Phys Chem A 2013; 117:12146-54. [DOI: 10.1021/jp4060704] [Citation(s) in RCA: 348] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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