TY - JOUR
T1 - Quantum theory of laser catalysis in one and three dimensions
AU - Seideman, Tamar
AU - Krause, Jeffrey L.
AU - Shapiro, Moshe
PY - 1991/12/1
Y1 - 1991/12/1
N2 - A theory of the laser catalysis of the H + H2 exchange reaction in the collinear configuration and in three dimensions is presented. The collinear H + H2 system in a strong laser field is treated by a method composed of a converged coupled channels expansion for the non-radiative processes, coupled with an exact partitioning technique for the interaction with the radiation. The method enables computations to be performed for an arbitrary number of field-intensities with very little effort beyond that required for a single-intensity computation. By studying the optical reactive line-shapes as a function of the scattering energy, the signature of the scattering resonances on optically induced reaction is unravelled. It is shown that when the collision energy is tuned to a resonance, laser catalysis results in selective vibrational excitation of the product H2 molecule. Implications of this effect for past and future experiments are discussed. A three-dimensional theory based on the same exact partitioning technique is then presented. In this case, the bound-free scattering amplitudes, which serve as input to the theory, are obtained by assuming separability in terms of a hindered-rotor vibrationally adiabatic basis. We use the theory to compute reactive differential and integral laser-catalysis cross-sections. We study the laser intensity dependence of the reactivity, the role played by isolated and overlapping power-broadened resonances and how the angle of the relative velocities of the reagents affects the reactivity.
AB - A theory of the laser catalysis of the H + H2 exchange reaction in the collinear configuration and in three dimensions is presented. The collinear H + H2 system in a strong laser field is treated by a method composed of a converged coupled channels expansion for the non-radiative processes, coupled with an exact partitioning technique for the interaction with the radiation. The method enables computations to be performed for an arbitrary number of field-intensities with very little effort beyond that required for a single-intensity computation. By studying the optical reactive line-shapes as a function of the scattering energy, the signature of the scattering resonances on optically induced reaction is unravelled. It is shown that when the collision energy is tuned to a resonance, laser catalysis results in selective vibrational excitation of the product H2 molecule. Implications of this effect for past and future experiments are discussed. A three-dimensional theory based on the same exact partitioning technique is then presented. In this case, the bound-free scattering amplitudes, which serve as input to the theory, are obtained by assuming separability in terms of a hindered-rotor vibrationally adiabatic basis. We use the theory to compute reactive differential and integral laser-catalysis cross-sections. We study the laser intensity dependence of the reactivity, the role played by isolated and overlapping power-broadened resonances and how the angle of the relative velocities of the reagents affects the reactivity.
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U2 - 10.1039/DC9919100271
DO - 10.1039/DC9919100271
M3 - Article
AN - SCOPUS:0004934888
SN - 0301-7249
VL - 91
SP - 271
EP - 288
JO - Faraday Discussions of the Chemical Society
JF - Faraday Discussions of the Chemical Society
ER -