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Kroes GJ. Computational approaches to dissociative chemisorption on metals: towards chemical accuracy. Phys Chem Chem Phys 2021; 23:8962-9048. [PMID: 33885053 DOI: 10.1039/d1cp00044f] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We review the state-of-the-art in the theory of dissociative chemisorption (DC) of small gas phase molecules on metal surfaces, which is important to modeling heterogeneous catalysis for practical reasons, and for achieving an understanding of the wealth of experimental information that exists for this topic, for fundamental reasons. We first give a quick overview of the experimental state of the field. Turning to the theory, we address the challenge that barrier heights (Eb, which are not observables) for DC on metals cannot yet be calculated with chemical accuracy, although embedded correlated wave function theory and diffusion Monte-Carlo are moving in this direction. For benchmarking, at present chemically accurate Eb can only be derived from dynamics calculations based on a semi-empirically derived density functional (DF), by computing a sticking curve and demonstrating that it is shifted from the curve measured in a supersonic beam experiment by no more than 1 kcal mol-1. The approach capable of delivering this accuracy is called the specific reaction parameter (SRP) approach to density functional theory (DFT). SRP-DFT relies on DFT and on dynamics calculations, which are most efficiently performed if a potential energy surface (PES) is available. We therefore present a brief review of the DFs that now exist, also considering their performance on databases for Eb for gas phase reactions and DC on metals, and for adsorption to metals. We also consider expressions for SRP-DFs and briefly discuss other electronic structure methods that have addressed the interaction of molecules with metal surfaces. An overview is presented of dynamical models, which make a distinction as to whether or not, and which dissipative channels are modeled, the dissipative channels being surface phonons and electronically non-adiabatic channels such as electron-hole pair excitation. We also discuss the dynamical methods that have been used, such as the quasi-classical trajectory method and quantum dynamical methods like the time-dependent wave packet method and the reaction path Hamiltonian method. Limits on the accuracy of these methods are discussed for DC of diatomic and polyatomic molecules on metal surfaces, paying particular attention to reduced dimensionality approximations that still have to be invoked in wave packet calculations on polyatomic molecules like CH4. We also address the accuracy of fitting methods, such as recent machine learning methods (like neural network methods) and the corrugation reducing procedure. In discussing the calculation of observables we emphasize the importance of modeling the properties of the supersonic beams in simulating the sticking probability curves measured in the associated experiments. We show that chemically accurate barrier heights have now been extracted for DC in 11 molecule-metal surface systems, some of which form the most accurate core of the only existing database of Eb for DC reactions on metal surfaces (SBH10). The SRP-DFs (or candidate SRP-DFs) that have been derived show transferability in many cases, i.e., they have been shown also to yield chemically accurate Eb for chemically related systems. This can in principle be exploited in simulating rates of catalyzed reactions on nano-particles containing facets and edges, as SRP-DFs may be transferable among systems in which a molecule dissociates on low index and stepped surfaces of the same metal. In many instances SRP-DFs have allowed important conclusions regarding the mechanisms underlying observed experimental trends. An important recent observation is that SRP-DFT based on semi-local exchange DFs has so far only been successful for systems for which the difference of the metal work function and the molecule's electron affinity exceeds 7 eV. A main challenge to SRP-DFT is to extend its applicability to the other systems, which involve a range of important DC reactions of e.g. O2, H2O, NH3, CO2, and CH3OH. Recent calculations employing a PES based on a screened hybrid exchange functional suggest that the road to success may be based on using exchange functionals of this category.
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Affiliation(s)
- Geert-Jan Kroes
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
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2
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Nogueira JJ, Sánchez-Coronilla A, Marques JM, Hase WL, Martínez-Núñez E, Vázquez SA. Intermolecular potentials for simulations of collisions of SiNCS+ and (CH3)2SiNCS+ ions with fluorinated self-assembled monolayers. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2011.02.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Waring C, King KL, Costen ML, McKendrick KG. Dynamics of the Gas−Liquid Interfacial Reaction of O(1D) with a Liquid Hydrocarbon. J Phys Chem A 2011; 115:7210-9. [DOI: 10.1021/jp200292n] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carla Waring
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Kerry L King
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Matthew L Costen
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Kenneth G McKendrick
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
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4
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Waring C, Bagot PAJ, Costen ML, McKendrick KG. Reactive Scattering as a Chemically Specific Analytical Probe of Liquid Surfaces. J Phys Chem Lett 2011; 2:12-18. [PMID: 26295207 DOI: 10.1021/jz1013032] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this Perspective, we highlight some recent progress in the reactive scattering of "chemical probe" species such as atoms or small radicals from liquid surfaces. We emphasize in particular the evolution of this area from purely dynamical studies of the scattering mechanism. The mechanistic understanding that has now been gained is sufficiently mature to allow the same methods to be used as an effective analytical tool. The use of this approach to measure liquid-surface composition and structure is illustrated through the scattering of O((3)P) atoms from a common, imidazolium-based family of ionic liquids.
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Affiliation(s)
- Carla Waring
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Paul A J Bagot
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Matthew L Costen
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Kenneth G McKendrick
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
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Layfield JP, Troya D. Theoretical study of the dynamics of F+alkanethiol self-assembled monolayer hydrogen-abstraction reactions. J Chem Phys 2010; 132:134307. [DOI: 10.1063/1.3364858] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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6
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Waring C, Bagot PAJ, Slattery JM, Costen ML, McKendrick KG. O(3P) Atoms as a Chemical Probe of Surface Ordering in Ionic Liquids. J Phys Chem A 2010; 114:4896-904. [DOI: 10.1021/jp912045j] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carla Waring
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Paul A. J. Bagot
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - John M. Slattery
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Matthew L. Costen
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Kenneth G. McKendrick
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
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7
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Yockel S, Schatz GC. Modeling O(3P) and Ar Scattering from the Ionic Liquid [emim][NO3] at 5 eV with Hybrid QM/MM Molecular Dynamics. J Phys Chem B 2010; 114:14241-8. [DOI: 10.1021/jp910707v] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Scott Yockel
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
| | - George C. Schatz
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
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Behr P, Scharfenort U, Zellner R. Collisions of noble gases with supercooled sulfuric acid-water solutions. Phys Chem Chem Phys 2009; 11:7292-302. [PMID: 19672541 DOI: 10.1039/b821751c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The collisions of hyperthermal noble gases (He, Ne, Ar, Kr, Xe) with supercooled binary sulfuric acid-water mixtures (57-77 wt%) were explored in the temperature range between 210 and 240 K. The experiments were performed by directing a molecular beam of the respective gases onto a continuously renewed liquid surface and monitoring the velocity of the scattered molecules by mass spectrometry. Depending on the initial translational energies and molecular masses, we observe both inelastic scattering from the surface as well as thermalization followed by subsequent desorption. The experiments indicate that the repulsive momentum transfer in the inelastic scattering channel increases with increasing mass of the impinging gas, while it is only weakly affected by the initial velocities. The final energy of the thermally desorbing atoms can always be approximated by a Maxwell-Boltzmann distribution equal to the liquid bulk phase temperature. The influence of the binary composition of the liquid phase is only noticeable in the case of Ne, whilst this dependence diminishes for gases with molecular masses >or=40 amu. The probability of thermalisation relative to inelastic scattering increases with the bulk phase temperature, independent of the molecular masses of the colliding gas. In contrast, the fractional energy transfer during collision does not increase with temperature, except for Neon. These results can be interpreted in the model framework of hard-sphere collisions of noble gases with the surface, during which water and sulfuric acid molecules interact independently with the impinging gas.
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Affiliation(s)
- Peter Behr
- Institute of Physical and Theoretical Chemistry, University of Duisburg-Essen, Essen, Germany
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Schweigert IV, Dunlap BI. Electronic structure and molecular dynamics of breaking the RO–NO2 bond. J Chem Phys 2009; 130:244110. [DOI: 10.1063/1.3155081] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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Barnes GL, Hase WL. NH4+ + CH4 Gas Phase Collisions as a Possible Analogue to Protonated Peptide/Surface Induced Dissociation. J Phys Chem A 2009; 113:7543-7. [DOI: 10.1021/jp900919s] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- George L. Barnes
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409
| | - William L. Hase
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409
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11
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Radak BK, Yockel S, Kim D, Schatz GC. Modeling Reactive Scattering of F(2P) at a Liquid Squalane Interface: A Hybrid QM/MM Molecular Dynamics Study. J Phys Chem A 2009; 113:7218-26. [DOI: 10.1021/jp809546r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brian K. Radak
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
| | - Scott Yockel
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
| | - Dongwook Kim
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
| | - George C. Schatz
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
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12
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Waring C, Bagot PAJ, Räisänen MT, Costen ML, McKendrick KG. Dynamics of the Reaction of O(3P) Atoms with Alkylthiol Self-assembled Monolayers. J Phys Chem A 2009; 113:4320-9. [DOI: 10.1021/jp8109868] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Carla Waring
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K. and School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, U.K
| | - Paul A. J. Bagot
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K. and School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, U.K
| | - Minna T. Räisänen
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K. and School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, U.K
| | - Matthew L. Costen
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K. and School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, U.K
| | - Kenneth G. McKendrick
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K. and School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, U.K
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Yang G, Guan J, Zhou L, Liu X, Han X, Bao X. First-principle studies on the exceptionally active triplet oxygen species in microporous zeolite materials: Reservation and catalysis. J Photochem Photobiol A Chem 2009. [DOI: 10.1016/j.jphotochem.2008.12.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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14
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Zolot AM, Dagdigian PJ, Nesbitt DJ. Quantum-state resolved reactive scattering at the gas-liquid interface: F+squalane (C30H62) dynamics via high-resolution infrared absorption of nascent HF(v,J). J Chem Phys 2008; 129:194705. [DOI: 10.1063/1.2973630] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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15
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Layfield JP, Owens MD, Troya D. Theoretical study of the dynamics of the H+CH4 and H+C2H6 reactions using a specific-reaction-parameter semiempirical Hamiltonian. J Chem Phys 2008; 128:194302. [DOI: 10.1063/1.2918358] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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16
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Vázquez SA, Morris JR, Rahaman A, Mazyar OA, Vayner G, Addepalli SV, Hase WL, Martínez-Núñez E. Inelastic Scattering Dynamics of Ar from a Perfluorinated Self-Assembled Monolayer Surface. J Phys Chem A 2007; 111:12785-94. [DOI: 10.1021/jp076431m] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Saulo A. Vázquez
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - John R. Morris
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - Asif Rahaman
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - Oleg A. Mazyar
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - Grigoriy Vayner
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - Srirangam V. Addepalli
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - William L. Hase
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - Emilio Martínez-Núñez
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
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17
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Kim D, Schatz GC. Theoretical Investigation of Hyperthermal Reactions at the Gas−Liquid Interface: O (3P) and Squalane. J Phys Chem A 2007; 111:5019-31. [PMID: 17511430 DOI: 10.1021/jp0700478] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hyperthermal collisions (5 eV) of ground-state atomic oxygen [O ((3)P)] with a liquid-saturated hydrocarbon, squalane (C(30)H(62)), have been studied using QM/MM hybrid "on-the-fly" direct dynamics. The surface structure of the liquid squalane is obtained from a classical molecular dynamics simulation using the OPLS-AA force field. The MSINDO semiempirical Hamiltonian is combined with OPLS-AA for the QM/MM calculations. In order to achieve a more consistent and efficient simulation of the collisions, we implemented a dynamic partitioning of the QM and MM atoms in which atoms are assigned to QM or MM regions based on their proximity to "seed" (open-shell) atoms that determine where bond making/breaking can occur. In addition, the number of seed atoms is allowed to increase or decrease as time evolves so that multiple reactive events can be described. The results show that H abstraction is the most important process for all incident angles, with H elimination, double H abstraction, and C-C bond cleavage also being important. A number of properties of these reactive channels, as well as inelastic nonreactive scattering, are investigated, including angular and translational energy distributions, the effect of incident collision angle, variation with depth of the reactive event within the liquid, with the reaction site on the hydrocarbon, and the effect of dynamics before and after reaction (direct reaction versus trapping reaction-desorption).
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Affiliation(s)
- Dongwook Kim
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
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Tasić U, Hein P, Troya D. Theoretical Study of the Dynamics of Ar Collisions with C2H6 and C2F6 at Hyperthermal Energy. J Phys Chem A 2007; 111:3618-32. [PMID: 17429956 DOI: 10.1021/jp071287q] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a classical-trajectory study of the dynamics of high-energy (5-12 eV) collisions between Ar atoms and the C2H6 and C2F6 molecules. We have constructed the potential-energy surfaces for these systems considering separately the Ar-molecule interactions (intermolecular potential) and the interactions within the molecule (intramolecular potential). The intermolecular surfaces consist of pairwise empirical potentials derived from high-accuracy ab initio calculations. The intramolecular potentials for C2H6 and C2F6 are described using specific-reaction-parameters semiempirical Hamiltonians and are calculated "on the fly", i.e., while the trajectories are evolving. Trajectory analysis shows that C2F6 absorbs more energy than C2H6 and is more susceptible to collision-induced dissociation (CID). C-C bond-breakage processes are more important than C-H or C-F bond breakage at the energies explored in this work. Analysis of the reaction mechanism for CID processes indicates that, although C-C breakage is mostly produced by side-on collisions, head-on collisions are more efficient in producing C-F or C-H dissociation. Our results suggest that high-energy collisions between closed-shell species of the natural low-Earth-orbit environment and spacecraft can contribute to the observed degradation of polymers that coat spacecraft surfaces.
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Affiliation(s)
- Uros Tasić
- Department of Chemistry, Virginia Tech, 107 Davidson Hall, Blacksburg, VA 24061-0212, USA
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Irving DL, Brenner DW. Diffusion on a Self-Assembled Monolayer: Molecular Modeling of a Bound + Mobile Lubricant. J Phys Chem B 2006; 110:15426-31. [PMID: 16884264 DOI: 10.1021/jp0609840] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The diffusion of tricresyl phosphate molecules on an octadecyltrichlorosilane self-assembled monolayer (SAM) was characterized using molecular dynamics simulations. The simulations predict that when placed on the top of a close-packed SAM, the molecules remain mobile on the surface with an isotropic diffusion activation energy of approximately 9 kJ/mol. In contrast, an anisotropic barrier that results from chain tilt within the SAM is predicted for diffusion into a defect created by reducing the alkane chain length within a cylinderical region of the surface. Once in the defect, the molecules become trapped by embedding part of the molecule into the side of the SAM.
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Affiliation(s)
- Douglas L Irving
- Department of Materials Science and Engineering, Campus Box 7907, North Carolina State University, Raleigh, North Carolina 27695-7907, USA.
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Zhang J, Upadhyaya HP, Brunsvold AL, Minton TK. Hyperthermal Reactions of O and O2 with a Hydrocarbon Surface: Direct C−C Bond Breakage by O and H-Atom Abstraction by O2. J Phys Chem B 2006; 110:12500-11. [PMID: 16800579 DOI: 10.1021/jp061521x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A C-C bond-breaking reaction has been observed when a beam containing hyperthermal oxygen was directed at a continuously refreshed saturated hydrocarbon liquid (squalane) surface. The dynamics of this C-C bond-breaking reaction have been investigated by monitoring time-of-flight and angular distributions of the volatile product, OCH3 or H2CO. The primary product is believed to be the methoxy radical, OCH3, but if this radical is highly internally excited, then it may undergo secondary dissociation to form formaldehyde, H2CO. Either the primary or the secondary product may scatter directly into the gas phase before thermal equilibrium with the surface is reached, or they may become trapped on the surface and desorb in thermal equilibrium with the surface. Direct, single-collision scattering events that produce a C-C bond-breaking product are described with a kinematic picture that allows the determination of the effective surface mass encountered by an incident O atom, the atom-surface collision energy in the center-of-mass frame, and the fraction of the center-of-mass collision energy that goes into translation of the scattered gaseous product and the recoiling surface fragment. The dynamical behavior of the C-C bond-breaking reaction is compared with that of the H-atom abstraction reaction, which was the subject of an earlier study. Another reaction, H-atom abstraction by O2 (which is present in the hyperthermal beam), has also been observed, and the dynamics of this reaction are compared with the inelastic scattering dynamics of O2 and the dynamics of H-atom abstraction by O. The dynamics involving direct inelastic and reactive scattering of O2 are also described in terms of a kinematic picture where the incident O2 molecule is viewed as interacting with a local region of the surface.
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Affiliation(s)
- Jianming Zhang
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA
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21
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Tasić US, Yan T, Hase WL. Dynamics of Energy Transfer in Collisions of O(3P) Atoms with a 1-Decanethiol Self-Assembled Monolayer Surface. J Phys Chem B 2006; 110:11863-77. [PMID: 16800489 DOI: 10.1021/jp0611065] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chemical dynamics simulations are reported of energy transfer in collisions of O(3P) atoms with a 300 K 1-decanethiol self-assembled monolayer (H-SAM) surface. The simulations are performed with a nonreactive potential energy surface, developed from PMP2/aug-cc-pVTZ calculations of the O(3P) + H-SAM intermolecular potential, and the simulation results represent the energy transfer dynamics in the absence of O(3P) reaction. Collisions energies E(i) of 0.12, 2.30, 11.2, 75.0, and 120.5 kcal/mol and incident angles theta(i) of 15, 30, 45, 60, and 75 degrees were considered in the study (theta(i) = 0 degrees is the surface normal). The translational energy distribution of the scattered O(3P) atoms, P(E(f)), may be deconvoluted into Boltzmann and non-Boltzmann components, with the former fraction identified as f(B). The trajectories are also analyzed in terms of three types; that is, direct scattering from and physisorption on the top of the H-SAM and penetration of the H-SAM. There are three energy regimes in the scattering dynamics. For the low E(i) values of 0.12 and 2.30 kcal/mol, physisorption is important and both f(B) and the average final translational energy of the scattered O(3P) atom, E(f), are nearly independent of the incident angle. The dynamics is much different for hyperthermal energies of 75.0 and 120.5 kcal/mol, where penetration of the surface is important. For hyperthermal collisions, the penetration probability decreases as theta(i) is increased, with a significant transition between theta(i) of 60 and 75 degrees . Hyperthermal penetration occurs upon initial surface impact and is more probable if the impinging O(3P) atom may move down a channel between the chains. For E(i) = 120.5 kcal/mol, 90% of the trajectories penetrate at theta(i) = 15 degrees , while only 3% penetrate at theta(i) = 75 degrees. For the former theta(i), the energy transfer to the surface is efficient with E(f) = 4.04 kcal/mol, but for the latter theta(i), E(f) = 85.3 kcal/mol! Particularly interesting penetrating trajectories are those in which O(3P) is trapped in the H-SAM for times exceeding 60 ps, linger near the Au substrate, and strike the Au substrate and scatter directly. For E(i) = 11.2 kcal/mol, there is a transition between the scattering dynamics for the low and hyperthermal collision energies. Additional detail in the energy transfer dynamics is obtained from the final polar and azimuthal angles, the residence time on/in the H-SAM, the minimum height with respect to the Au substrate, and the number of inner turning points in the O-atom's velocity. Calculated values of E(f) vs the final polar angle, theta(f), are in qualitative agreement with experiment. The O(3P) + H-SAM nonreactive energy transfer dynamics, for E(i) of 11.2 kcal/mol and lower, are very similar to previously reported Ne + H-SAM simulations.
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Affiliation(s)
- Uros S Tasić
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, USA
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Vayner G, Alexeev Y, Wang J, Windus TL, Hase WL. Ab initio and analytic intermolecular potentials for Ar-CF4. J Phys Chem A 2006; 110:3174-8. [PMID: 16509641 DOI: 10.1021/jp054592p] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Ab initio calculations at the CCSD(T) level of theory were performed to characterize the Ar + CF4 intermolecular potential. Potential energy curves were calculated with the aug-cc-pVTZ basis set, and with and without a correction for basis set superposition error (BSSE). Additional calculations were performed with other correlation consistent basis sets to extrapolate the Ar-CF4 potential energy minimum to the complete basis set (CBS) limit. Both the size of the basis set and BSSE have substantial effects on the Ar + CF4 potential. Calculations with the aug-cc-pVTZ basis set, and with a BSSE correction, appear to give a good representation of the BSSE corrected potential at the CBS limit. In addition, MP2 theory is found to give potential energies in very good agreement with those determined by the much higher level CCSD(T) theory. Two model analytic potential energy functions were determined for Ar + CF4. One is a fit to the aug-cc-pVTZ calculations with a BSSE correction. The second was derived by fitting an average BSSE corrected potential, which is an average of the CCSD(T)/aug-cc-pVTZ potentials with and without a BSSE correction. These analytic functions are written as a sum of two-body potentials and excellent fits to the ab initio potentials are obtained by representing each two-body interaction as a Buckingham potential.
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Affiliation(s)
- Grigoriy Vayner
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
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Abstract
The reaction of 5-40 eV O(+) and Ne(+) ions with alkanethiolate and semifluorinated alkanethiolate self-assembled monolayers (SAMs) is studied under ultrahigh vacuum (UHV) conditions. Whereas Ne(+) simply sputters fragments from the surface, O(+) can also abstract surface atoms and break C-C bonds in both the hydrocarbon and fluorocarbon SAM chains. Isotopic labeling experiments reveal that O(+) initially abstracts hydrogen atoms from the outermost two carbon atoms on an alkanethiolate SAM chain. However, the position of the isotopic label quickly becomes scrambled along the chain as the SAM is damaged through continuous ion bombardment. Scanning tunneling microscopy (STM) monitors changes in the SAM conformational structure at various stages during 5 eV ion bombardment. STM images indicate that O(+) reacts less efficiently with dodecanethiolate molecules packed internally within a structural domain than it does with molecules adsorbed at domain boundaries or near defect sites. STM images recorded after Ne(+) bombardment suggest that Ne(+) attacks the SAM exclusively near the domain boundaries. Taken collectively, these experiments advance our understanding of the degradation pathways suffered by polymeric satellite materials in the low-earth orbit (LEO) space environment.
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Affiliation(s)
- Xiangdong Qin
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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Troya D. Ab initioand direct quasiclassical-trajectory study of the F+CH4→HF+CH3 reaction. J Chem Phys 2005; 123:214305. [PMID: 16356046 DOI: 10.1063/1.2126972] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present an electronic structure and dynamics study of the F+CH4-->HF+CH3 reaction. CCSD(T)/aug-cc-pVDZ geometry optimizations, harmonic-frequency, and energy calculations indicate that the potential-energy surface is remarkably isotropic near the transition state. In addition, while the saddle-point F-H-C angle is 180 degrees using MP2 methods, CCSD(T) geometry optimizations predict a bent transition state, with a 153 degrees F-H-C angle. We use these high-quality ab initio data to reparametrize the parameter-model 3 (PM3) semiempirical Hamiltonian so that calculations with the improved Hamiltonian and employing restricted open-shell wave functions agree with the higher accuracy data. Using this specific-reaction-parameter PM3 semiempirical Hamiltonian (SRP-PM3), we investigate the reaction dynamics by propagating quasiclassical trajectories. The results of our calculations using the SRP-PM3 Hamiltonian are compared with experiments and with the estimates of two recently reported potential-energy surfaces. The trajectory calculations using the SRP-PM3 Hamiltonian reproduce quantitatively the measured HF vibrational distributions. The calculations also agree with the experimental HF rotational distributions and capture the essential features of the excitation function. The results of the SRP semiempirical Hamiltonian developed here clearly improve over those using the two prior potential-energy surfaces and suggest that reparametrization of semiempirical Hamiltonians is a promising strategy to develop accurate potential-energy surfaces for reaction dynamics studies of polyatomic systems.
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Affiliation(s)
- Diego Troya
- Department of Chemistry, Virginia Tech, 107 Davidson Hall, Blacksburg, Virginia 24061-0212, USA.
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Gorham J, Torres J, Wolfe G, d'Agostino A, Fairbrother DH. Surface Reactions of Molecular and Atomic Oxygen with Carbon Phosphide Films. J Phys Chem B 2005; 109:20379-86. [PMID: 16853637 DOI: 10.1021/jp0521196] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The surface reactions of atomic and molecular oxygen with carbon phosphide films have been studied using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Carbon phosphide films were produced by ion implantation of trimethylphosphine into polyethylene. Atmospheric oxidation of carbon phosphide films was dominated by phosphorus oxidation and generated a carbon-containing phosphate surface film. This oxidized surface layer acted as an effective diffusion barrier, limiting the depth of phosphorus oxidation within the carbon phosphide film to < 3 nm. The effect of atomic oxygen (AO) exposure on this oxidized carbon phosphide layer was subsequently probed in situ using XPS. Initially AO exposure resulted in a loss of carbon atoms from the surface, but increased the surface concentration of phosphorus atoms as well as the degree of phosphorus oxidation. For more prolonged AO exposures, a highly oxidized phosphate surface layer formed that appeared to be inert toward further AO-mediated erosion. By utilizing phosphorus-containing hydrocarbon thin films, the phosphorus oxides produced during exposure to AO were found to desorb at temperatures >500 K under vacuum conditions. Results from this study suggest that carbon phosphide films can be used as AO-resistant surface coatings on polymers.
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Affiliation(s)
- Justin Gorham
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, MA 21218, USA
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Troya D, García-Molina E. Quasiclassical Trajectory Study of the O(3P) + CH4→ OH + CH3Reaction with a Specific Reaction Parameters Semiempirical Hamiltonian. J Phys Chem A 2005; 109:3015-23. [PMID: 16833625 DOI: 10.1021/jp044304+] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present a theoretical study of the O(3P) + CH4 --> OH + CH3 reaction using electronic structure, kinetics, and dynamics calculations. We calculate a grid of ab initio points at the PMP2/AUG-cc-pVDZ level to characterize the potential energy surface in regions of up to 1.3 eV above reagents. This grid of ab initio points is used to derive a set of specific reaction parameters (SRP) for the MSINDO semiempirical Hamiltonian. The resulting SRP-MSINDO Hamiltonian improves the quality of the standard Hamiltonian, particularly in regions of the potential energy surface beyond the minimum-energy reaction path. Quasiclassical-trajectory calculations are used to study the reaction dynamics with the original and the improved MSINDO semiempirical Hamiltonians, and a prior surface. The SRP-MSINDO semiempirical Hamiltonian yields OH rotational distributions in agreement with experimental results, improving over the results of the other surfaces. Thermal rate constants estimated with Variational Transition State Theory using the SRP-MSINDO Hamiltonian are also in agreement with experiments. Our results indicate that reparametrized semiempirical Hamiltonians are a good alternative to generating potential energy surfaces for accurate dynamics studies of polyatomic reactions.
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Affiliation(s)
- Diego Troya
- Department of Chemistry, Virginia Tech, 107 Davidson Hall, Blacksburg Virginia, 2060-0212, USA.
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Köhler SPK, Allan M, Kelso H, Henderson DA, McKendrick KG. The effects of surface temperature on the gas-liquid interfacial reaction dynamics of O(3P)+squalane. J Chem Phys 2005; 122:024712. [PMID: 15638619 DOI: 10.1063/1.1835268] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OH/OD product state distributions arising from the reaction of gas-phase O(3P) atoms at the surface of the liquid hydrocarbon squalane C30H62/C30D62 have been measured. The O(3P) atoms were generated by 355 nm laser photolysis of NO2 at a low pressure above the continually refreshed liquid. It has been shown unambiguously that the hydroxyl radicals detected by laser-induced fluorescence originate from the squalane surface. The gas-phase OH/OD rotational populations are found to be partially sensitive to the liquid temperature, but do not adapt to it completely. In addition, rotational temperatures for OH/OD(v'=1) are consistently colder (by 34+/-5 K) than those for OH/OD(v'=0). This is reminiscent of, but less pronounced than, a similar effect in the well-studied homogeneous gas-phase reaction of O(3P) with smaller hydrocarbons. We conclude that the rotational distributions are composed of two different components. One originates from a direct abstraction mechanism with product characteristics similar to those in the gas phase. The other is a trapping-desorption process yielding a thermal, Boltzmann-like distribution close to the surface temperature. This conclusion is consistent with that reached previously from independent measurements of OH product velocity distributions in complementary molecular-beam scattering experiments. It is further supported by the temporal profiles of OH/OD laser-induced fluorescence signals as a function of distance from the surface observed in the current experiments. The vibrational branching ratios for (v'=1)/(v'=0) for OH and OD have been found to be (0.07+/-0.02) and (0.30+/-0.10), respectively. The detection of vibrationally excited hydroxyl radicals suggests that secondary and/or tertiary hydrogen atoms may be accessible to the attacking oxygen atoms.
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Affiliation(s)
- Sven P K Köhler
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
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Yan T, Doubleday C, Hase WL. A PM3-SRP + Analytic Function Potential Energy Surface Model for O(3P) Reactions with Alkanes. Application to O(3P) + Ethane†. J Phys Chem A 2004. [DOI: 10.1021/jp048150+] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Troya * D, Schatz † GC. Hyperthermal chemistry in the gas phase and on surfaces: theoretical studies. INT REV PHYS CHEM 2004. [DOI: 10.1080/0144235042000298484] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Sun L, Chang E, Song K, Hase WL. Transition state dynamics and a QM/MM model for the Cl + C2H5Cl SN2 reaction. CAN J CHEM 2004. [DOI: 10.1139/v04-082] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A MP2/6-31G* direct dynamics simulation is used to study the dynamics of the central barrier [Cl-C2H5-Cl] for the Cl + C2H5 SN2 reaction. The majority of the trajectories move off the central barrier to form the ClC2H5Cl complex and appear to undergo efficient IVR as assumed by RRKM theory. However, some of the trajectories move directly to products without forming the complex, a non-RRKM result. A hydrogen atom link-atom QM/MM model is described for studying the dynamics of [X-CH2R-Y] central barriers with the -R substituent. The model is used to calculate vibrational frequencies for the [Cl-C2H5-Cl] central barrier.Key words: SN2 reaction dynamics, RRKM theory, QM/MM model, central barrier dynamics, direct dynamics classical trajectories.
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Yan T, Hase WL, Doubleday C. Energetics, transition states, and intrinsic reaction coordinates for reactions associated with O(3P) processing of hydrocarbon materials. J Chem Phys 2004; 120:9253-65. [PMID: 15267862 DOI: 10.1063/1.1705574] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Electronic structure calculations based on multiconfiguration wave functions are used to investigate a set of archetypal reactions relevant to O(3P) processing of hydrocarbon molecules and surfaces. These include O(3P) reactions with methane and ethane to give OH plus methyl or ethyl radicals, O(3P) + ethane to give CH3O + CH3, and secondary reactions of the OH product radical with ethane and the ethyl radical. Geometry optimization is carried out with CASSCF/cc-pVTZ for all reactions, and with CASPT2/cc-pVTZ for O(3P) + methane/ethane. Single-point energy corrections are applied with CASPT2, CASPT3, and MRCI + Q with the cc-pVTZ and cc-pVQZ basis sets, and the energies extrapolated to the complete basis set limit (CBL). Where comparison of computed barriers and energies of reaction with experiment is possible, the agreement is good to excellent. The best agreement (within experimental error) is found for MRCI + Q/CBL applied to O(3P) + methane. For the other reactions, CASPT2/CBL and MRCI + Q/CBL predictions differ from experiment by 1-5 kcal/mol for 0 K enthalpies of reaction, and are within 1 kcal/mol of the best-estimate experimental range of 0 K barriers for O(3P) + ethane and OH + ethane. The accuracy of MRCI + Q/CBL is limited mainly by the quality of the active space. CASPT2/CBL barriers are consistently lower than MRCI + Q/CBL barriers with identical reference spaces.
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Affiliation(s)
- Tianying Yan
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
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Troya D, Schatz GC. Theoretical studies of hyperthermal O(3P) collisions with hydrocarbon self-assembled monolayers. J Chem Phys 2004; 120:7696-707. [PMID: 15267681 DOI: 10.1063/1.1688312] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a dynamics study of inelastic and reactive scattering processes in collisions of hyperthermal (5 eV) O(3P) atoms with a hydrocarbon self-assembled monolayer (SAM). Molecular-dynamics simulations are carried out using a quantum mechanics/molecular mechanics (QM/MM) interaction potential that uses a high quality semiempirical Hamiltonian for the QM part and the MM3 force field for the MM part. A variety of products coming from reaction are identified, including H abstraction to generate OH, O atom addition to the SAM with subsequent elimination of H atoms, and direct C-C breakage. The C-C breakage mechanism provides a pathway for significant surface mass loss in single reactive events whereas the O addition-H elimination channel leads to surface oxidation. Reaction probabilities, product energy, and angular distributions are examined to gain insight on polymer erosion in low Earth orbit conditions and on fundamentals of inelastic and reactive hyperthermal gas-surface interactions.
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Affiliation(s)
- Diego Troya
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, USA
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Kelso H, Köhler SPK, Henderson DA, McKendrick KG. Dynamics of the gas–liquid interfacial reaction of O(3P) atoms with hydrocarbons. J Chem Phys 2003. [DOI: 10.1063/1.1624833] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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34
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Troya D, Pascual RZ, Schatz GC. Theoretical Studies of the O(3P) + Methane Reaction. J Phys Chem A 2003. [DOI: 10.1021/jp034027r] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Diego Troya
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Ilinois 60208-3113, and Department of Chemistry, CAS-University of Southern Mindanao, Kabacan, Cotabato, Philippines 9407
| | - Ronald Z. Pascual
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Ilinois 60208-3113, and Department of Chemistry, CAS-University of Southern Mindanao, Kabacan, Cotabato, Philippines 9407
| | - George C. Schatz
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Ilinois 60208-3113, and Department of Chemistry, CAS-University of Southern Mindanao, Kabacan, Cotabato, Philippines 9407
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Troya D, Pascual RZ, Garton DJ, Minton TK, Schatz GC. Theoretical Studies of the O(3P) + Ethane Reaction. J Phys Chem A 2003. [DOI: 10.1021/jp034028j] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Diego Troya
- Chemistry Department, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, Chemistry Department, CAS−University of Southern Mindanao, Kabacan, Cotabato, Philippines 9407, and Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717
| | - Ronald Z. Pascual
- Chemistry Department, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, Chemistry Department, CAS−University of Southern Mindanao, Kabacan, Cotabato, Philippines 9407, and Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717
| | - Donna J. Garton
- Chemistry Department, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, Chemistry Department, CAS−University of Southern Mindanao, Kabacan, Cotabato, Philippines 9407, and Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717
| | - Timothy K. Minton
- Chemistry Department, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, Chemistry Department, CAS−University of Southern Mindanao, Kabacan, Cotabato, Philippines 9407, and Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717
| | - George C. Schatz
- Chemistry Department, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, Chemistry Department, CAS−University of Southern Mindanao, Kabacan, Cotabato, Philippines 9407, and Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717
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Mann DJ, Halls MD, Hase WL. Direct Dynamics Studies of CO-Assisted Carbon Nanotube Growth. J Phys Chem B 2002. [DOI: 10.1021/jp0255435] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David J. Mann
- Scientific Simulation and Modeling Group, Zyvex Corporation, Richardson, Texas 75081
| | - Mathew D. Halls
- Scientific Simulation and Modeling Group, Zyvex Corporation, Richardson, Texas 75081
| | - William L. Hase
- Department of Chemistry and Institute for Scientific Computing, Wayne State University, Detroit, Michigan 48202
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37
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Zhang J, Garton DJ, Minton TK. Reactive and inelastic scattering dynamics of hyperthermal oxygen atoms on a saturated hydrocarbon surface. J Chem Phys 2002. [DOI: 10.1063/1.1460858] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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