Laser-induced chemical reactions. [H + H/sub 2/; F + H/sub 2/; H + HF; Cl + H/sub 2/; H + HCl; H + LiF]
A classical model for the interaction of laser radiation with a molecular system is derived. This model is used to study the enhancement of a chemical reaction via a collision induced absorption. It was found that an infrared laser will in general enhance the rate of a chemical reaction, even if the reactants are infrared inactive. Results for an illustrative analytically solvable model are presented, as well as results from classical trajectory studies on a number of systems. The collision induced absorption spectrum in these systems can be written as the Fourier transform of a particular dipole correlation function. This is used to obtain the collision induced absorption spectrum for a state-selected, mono-energetic reactive collision system. Examples treated are a one-dimensional barrier problem, reactive and nonreactive collisions of H + H/sub 2/, and a modified H + H/sub 2/ potential energy surface which leads to a collision intermediate. An extension of the classical model to treat laser-induced electronically nonadiabatic collision processes is constructed. The model treats all degrees of freedom, molecular, electronic and radiation, in a dynamically consistent framework within classical mechanics. Application is made to several systems. Several interesting phenomena are discovered including a Franck-Condon-like effect causing maxima in the reaction probability at energies much below the classical threshold, laser de-enhancement of chemical reactions and an isotope effect. In order to assess the validity of the classical model for electronically nonadiabatic process (without a laser field), a model problem involving energy transfer in a collinear atom-diatom system is studied, and the results compared to the available quantum mechanical calculation. The calculations are in qualitative agreement.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6353067
- Report Number(s):
- LBL-12089; ON: DE81023032; TRN: 81-010842
- Resource Relation:
- Other Information: Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHLORINE
ATOM-MOLECULE COLLISIONS
FLUORINE
HYDROCHLORIC ACID
HYDROFLUORIC ACID
HYDROGEN
LITHIUM FLUORIDES
CHEMICAL REACTION KINETICS
ENERGY TRANSFER
INFRARED RADIATION
LASER RADIATION
MOLECULES
ONE-DIMENSIONAL CALCULATIONS
ALKALI METAL COMPOUNDS
ATOM COLLISIONS
COLLISIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HALOGENS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
KINETICS
LITHIUM COMPOUNDS
LITHIUM HALIDES
MOLECULE COLLISIONS
NONMETALS
RADIATIONS
REACTION KINETICS
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena