Unusual mechanism for H{sub 3}{sup +} formation from ethane as obtained by femtosecond laser pulse ionization and quantum chemical calculations

Journal Article · Mon Mar 21 00:00:00 EDT 2011 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3561311· OSTI ID:21560053

Kraus, Peter M; Schwarzer, Martin C; Schirmel, Nora; Urbasch, Gunter; Frenking, Gernot; Weitzel, Karl-Michael ^[1]

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1. Fachbereich Chemie, Physikalische Chemie, Philipps-Universitaet Marburg, Hans-Meerwein-Strasse, D-35032 Marburg (Germany)

The formation of H{sub 3}{sup +} from saturated hydrocarbon molecules represents a prototype of a complex chemical process, involving the breaking and the making of chemical bonds. We present a combined theoretical and experimental investigation providing for the first time an understanding of the mechanism of H{sub 3}{sup +} formation at the molecular level. The experimental approach involves femtosecond laser pulse ionization of ethane leading to H{sub 3}{sup +} ions with kinetic energies on the order of 4 to 6.5 eV. The theoretical approach involves high-level quantum chemical calculation of the complete reaction path. The calculations confirm that the process takes place on the potential energy surface of the ethane dication. A surprising result of the theoretical investigation is, that the transition state of the process can be formally regarded as a H{sub 2} molecule attached to a C{sub 2}H{sub 4}{sup 2+} entity but IRC calculations show that it belongs to the reaction channel yielding C{sub 2}H{sub 3}{sup +}+ H{sub 3}{sup +}. Experimentally measured kinetic energies of the correlated H{sub 3}{sup +} and C{sub 2}H{sub 3}{sup +} ions confirm the reaction path suggested by theory.

• OSTI ID: 21560053
• Journal Information: Journal of Chemical Physics, Vol. 134, Issue 11; Other Information: DOI: 10.1063/1.3561311; (c) 2011 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
CHEMICAL BONDS
COMPLEXES
DISSOCIATION
ETHANE
HYDROGEN
HYDROGEN IONS 3 PLUS
KINETIC ENERGY
LASERS
MOLECULES
MULTI-PHOTON PROCESSES
PHOTOIONIZATION
PHOTOLYSIS
POTENTIAL ENERGY
PULSES
REACTION KINETICS
SURFACES
ALKANES
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTS
ENERGY
HYDROCARBONS
HYDROGEN IONS
IONIZATION
IONS
KINETICS
MOLECULAR IONS
NONMETALS
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS