A theoretical approach to the photochemical activation of matrix isolated aluminum atoms and their reaction with methane

Journal Article · Sun Nov 07 00:00:00 EDT 2010 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3499813· OSTI ID:21559945

Pacheco-Blas, M A; Novaro, O A ^[1]; Pacheco-Sanchez, J H ^[2]

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1. Instituto de Fisica, Universidad Nacional Autonoma de Mexico, AP 20-364, Mexico 01000 Distrito Federal (Mexico)
2. Instituto Tecnologico de Toluca, Edo. Mex., AP 890, Metepec 52140 (Mexico)

The photochemical activation of Al atoms in cryogenic matrices to induce their reaction with methane has been experimentally studied before. Here, a theoretical study of the nonadiabatic transition probabilities for the ground ({sup 2}P:3s{sup 2}3p{sup 1}) and the lowest excited states ({sup 2}S:3s{sup 2}4s{sup 1} and {sup 2}D:3s{sup 2}3d{sup 1}) of an aluminum atom interacting with a methane molecule (CH{sub 4}) was carried out through ab initio Hartree-Fock self-consistent field calculations. This was followed by a multiconfigurational study of the correlation energy obtained by extensive variational and perturbational configuration interaction analyses using the CIPSI program. The {sup 2}D state is readily inserted into a C-H bond, this being a prelude to a sequence of avoided crossings with the initially repulsive (to CH{sub 4}) lower lying states {sup 2}P and {sup 2}S. We then use a direct extension of the Landau-Zener theory to obtain transition probabilities at each avoided crossing, allowing the formation of an HAlCH{sub 3} intermediate that eventually leads to the final pair of products H+AlCH{sub 3} and HAl+CH{sub 3}.

• OSTI ID: 21559945
• Journal Information: Journal of Chemical Physics, Vol. 133, Issue 17; Other Information: DOI: 10.1063/1.3499813; (c) 2010 American Institute of Physics; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALUMINIUM
ATOM-MOLECULE COLLISIONS
ATOMS
CHEMICAL BONDS
CONFIGURATION INTERACTION
ELECTRON CORRELATION
EXCITED STATES
GROUND STATES
HARTREE-FOCK METHOD
MATRICES
METHANE
MOLECULES
PHOTOCHEMISTRY
POTENTIAL ENERGY
PROBABILITY
REACTION KINETICS
SELF-CONSISTENT FIELD
SURFACES
ALKANES
APPROXIMATIONS
ATOM COLLISIONS
CALCULATION METHODS
CHEMISTRY
COLLISIONS
CORRELATIONS
ELEMENTS
ENERGY
ENERGY LEVELS
HYDROCARBONS
KINETICS
METALS
MOLECULE COLLISIONS
ORGANIC COMPOUNDS