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Peng Y, Zhang H. Mechanism and Kinetics of Methane Combustion. Part II: Potential Energy Surface for Hydrogen-Abstraction Reaction of CH 4 + O( 3P). J Phys Chem A 2022; 126:1946-1959. [PMID: 35298157 DOI: 10.1021/acs.jpca.1c10860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Methane combustion plays an important role in various fields such as combustion chemistry and atmospheric chemistry of the stratosphere. Highly accurate study of its initial reaction remains a key challenge. Here, through extensive studies with a state-of-the-art ab initio and neural network method, we present a potential energy surface of the O(3P) + CH4 → OH + CH3 reaction on the ground state 13A and the first excited state 23A. In this work, the energies of 10 167 points covering all important regions are obtained with state-averaged complete active space self-consistent field calculations and then fitted using the Levenberg-Marquardt algorithm with a root-mean-square error of 0.391 and 0.442 kcal/mol for the 13A and 23A states, respectively. This study explores the characteristics of the radical van der Waals (VdW) complex and reveals a detailed mechanism of the methane combustion initial reaction. Within the scope of this mechanism, this surface gives a fairly accurate description of the regions around the saddle point, conical intersection, and vdW wells in the entrance for efficient computational simulations. As a theoretical study on a prototypical polyatomic reaction, it is hopeful that this work will modify our understanding of the primary process in hydrocarbon combustion.
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Affiliation(s)
- Ya Peng
- Department of Engineering Physics, Tsinghua University, Beijing 100084, P.R. China
| | - Hui Zhang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, P.R. China
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2
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Ausfelder F, McKendrick KG. The Dynamics of Reactions of O(3P) Atoms with Saturated Hydrocarbons and Related Compounds. PROGRESS IN REACTION KINETICS AND MECHANISM 2019. [DOI: 10.3184/007967400103165164] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We review the experimental and theoretical work which has been carried out on the dynamics of reactions of O(3P) with saturated hydrocarbons and related systems. We concentrate primarily on gas phase reactions, but also cover in less detail the more limited work on condensed phase and interfacial reactions. Although O(3P) + saturated alkane reactions are the primary focus, the dominant features of their dynamics are compared and contrasted with those of unsaturated alkanes, functionalised alkanes, and inorganic hydrides (including silanes, germanes, H2S, and hydrogen halides). The principal experimental techniques are reviewed. The experimentally determined quantities are identified, including excitation functions, OH rovibrational and fine-structure partitioning, the rather limited equivalent results for the organic radical co-product, and differential cross-sections. The dynamical conclusions that have been inferred are discussed and compared with the predictions of various levels of theory from semi-empirical models through to rigorous ab initio treatments. For many organic systems, most of the evidence points to OH being formed via a direct abstraction mechanism in which the O(3P) atom attacks along an isolated C–H bond. Outstanding problems with this basic interpretation and gaps in the current knowledge base are identified.
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Affiliation(s)
- Florian Ausfelder
- Department of Chemisty, The University of Edinburgh, Edinburgh EH9 3JJ, UK
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Grein F. Ab initio studies of the van der Waals complex CH4–O2. CH···O and CX···O interactions in halomethane X
n
CH4−n–O2 complexes (X = F, Cl; n = 1, 2, 3). Theor Chem Acc 2018. [DOI: 10.1007/s00214-018-2250-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Cappelletti D, Aquilanti V, Bartocci A, Nunzi F, Tarantelli F, Belpassi L, Pirani F. Interaction of O2 with CH4, CF4, and CCl4 by Molecular Beam Scattering Experiments and Theoretical Calculations. J Phys Chem A 2016; 120:5197-207. [PMID: 26938313 DOI: 10.1021/acs.jpca.6b00948] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gas phase collisions of O2 by CH4, CF4, and CCl4 have been investigated with the molecular beam technique by measuring both the integral cross section value, Q, and its dependence on the collision velocity, v. The adopted experimental conditions have been appropriate to resolve the oscillating "glory" pattern, a quantum interference effect controlled by the features of the intermolecular interaction, for all the three case studies. The analysis of the Q(v) data, performed by adopting a suitable representation of the intermolecular potential function, provided the basic features of the anisotropic potential energy surfaces at intermediate and large separation distances and information on the relative role of the physically relevant types of contributions to the global interaction. The present work demonstrates that while O2-CH4 and O2-CF4 are basically bound through the balance between size (Pauli) repulsion and dispersion attraction, an appreaciable intermolecular bond stabilization by charge transfer is operative in O2-CCl4. Ab initio calculations of the strength of the interaction, coupled with detailed analysis of electronic charge displacement promoted by the formation of the dimer, fully rationalizes the experimental findings. This investigation indicates that the interactions of O2, when averaged over its relative orientations, are similar to that of a noble gas (Ng), specifically Ar. We also show that the binding energy in the basic configurations of the prototypical Ng-CF4,CCl4 systems [ Cappelletti , D. ; Chem. Eur. J. 2015 , 21 , 6234 - 6240 ] can be reconstructed by using the interactions in Ng-F and Ng-Cl systems, previously characterized by molecular beam scattering experiments of state-selected halogen atom beams. This information is fundamental to approach the modeling of the weak intermolecular halogen bond. On the basis of the electronic polarizability, this also confirms [ Aquilanti , V. ; Angew. Chem., Int. Ed. 2005 , 44 , 2356 - 2360 ] that O2 can be taken as a proper reference partner for simulating the behavior of some basic noncovalent components of the interactions involving water. Present results are of fundamental relevance to build up the force field controlling the hydrophobic behavior of prototypical apolar CX4 (X = H, F, Cl) molecules.
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Affiliation(s)
- David Cappelletti
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia , Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Vincenzo Aquilanti
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia , Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Alessio Bartocci
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia , Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Francesca Nunzi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia , Via Elce di Sotto 8, 06123 Perugia, Italy.,CNR-Istituto di Scienze e Tecnologie Molecolari, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Francesco Tarantelli
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia , Via Elce di Sotto 8, 06123 Perugia, Italy.,CNR-Istituto di Scienze e Tecnologie Molecolari, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Leonardo Belpassi
- CNR-Istituto di Scienze e Tecnologie Molecolari, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Fernando Pirani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia , Via Elce di Sotto 8, 06123 Perugia, Italy
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Cappelletti D, Bartocci A, Frati F, Roncaratti LF, Belpassi L, Tarantelli F, Lakshmi PA, Arunan E, Pirani F. H2O–CH4and H2S–CH4complexes: a direct comparison through molecular beam experiments and ab initio calculations. Phys Chem Chem Phys 2015; 17:30613-23. [DOI: 10.1039/c5cp03704b] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electron density redistribution upon the formation of the water–methane complex arises from polarisation and charge transfer effects.
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Affiliation(s)
- David Cappelletti
- Dipartimento di Chimica
- Biologia e Biotecnologie
- Università di Perugia
- Italy
| | - Alessio Bartocci
- Dipartimento di Chimica
- Biologia e Biotecnologie
- Università di Perugia
- Italy
| | - Federica Frati
- Dipartimento di Chimica
- Biologia e Biotecnologie
- Università di Perugia
- Italy
| | - Luiz F. Roncaratti
- Dipartimento di Chimica
- Biologia e Biotecnologie
- Università di Perugia
- Italy
| | | | | | | | - Elangannan Arunan
- Indian Institute of Science
- Dept. Inorgan. & Phys. Chem
- Bangalore 560012
- India
| | - Fernando Pirani
- Dipartimento di Chimica
- Biologia e Biotecnologie
- Università di Perugia
- Italy
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Seyed Matin N, Jalili AH. Molecular-Dynamics Simulation of a Methane–Oxygen Mixture: Prediction ofP–V–TData and Evaluation of Effective Pair Potential Models. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2005. [DOI: 10.1246/bcsj.78.2105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Aquilanti V, Cappelletti D, Pirani F. Magnetically selected beams of atomic chlorine: measurement of long-range features of the chlorine–hydrogen and chlorine–methane potential-energy surfaces. ACTA ACUST UNITED AC 1993. [DOI: 10.1039/ft9938901467] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Cambi R, Cappelletti D, Liuti G, Pirani F. Generalized correlations in terms of polarizability for van der Waals interaction potential parameter calculations. J Chem Phys 1991. [DOI: 10.1063/1.461035] [Citation(s) in RCA: 297] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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