Laser-Induced Chemical Reactions: Survey of the Literature, 1965–1979

The Early Era of Laser-Selective Chemistry 1960∼1985: Roots of Modern Quantum Control

“…In 1981, a comprehensive listing of such studies (from 1965 to 1979) was tabulated by reactant, product, and excitation source. 63 Most of the studies involved the use of the CO 2 laser because it was commercially available, robust, powerful, and tunable in the region of ∼9.2 μm to ∼10.8 μm. In general, experiments aiming for laser-induced reactions were done in a manner that may best be referred to as seeing what works.…”

“…The compilation referred to above separated studies where the laser-induced chemistry was clearly the result of thermal heating from those which were "...apparently directly driven by vibrational excitation...", as stated by the author, J. Steinfeld (p 244). 63 A typical example of the latter studies would involve the laser selectively exciting a target molecule, generally within a low-pressure gas, and the ensuing unimolecular reaction would happen before any intermolecular energy exchange. 64 But, despite selectively exciting target molecules, e.g., CH 2 F-CH 2 Br in ref 64, the reactions hoped for (i.e., in the case of the indicated molecule with the preferential goal of concerted elimination of HF) could not be enhanced beyond the predictions of the RRKM theory.…”

“…The enthusiasm generated by the prospect of laser-selective chemistry is clearly demonstrated by the exponential increase in the number of studies performed throughout the 1970s as Figure shows. The compilation referred to above separated studies where the laser-induced chemistry was clearly the result of thermal heating from those which were “ ...apparently directly driven by vibrational excitation... ”, as stated by the author, J. Steinfeld (p 244) . A typical example of the latter studies would involve the laser selectively exciting a target molecule, generally within a low-pressure gas, and the ensuing unimolecular reaction would happen before any intermolecular energy exchange .…”