Accession Number : AD0716004

Title :   Ultrarapid-Scan Infrared Spectroscopic Study of Extremely Reactive Molecules and of Infrared Lasers.

Descriptive Note : Final rept. 1 Feb 68-31 Jan 70,

Corporate Author : CALIFORNIA UNIV BERKELEY DEPT OF CHEMISTRY

Personal Author(s) : Pimentel,George C.

Report Date : OCT 1970

Pagination or Media Count : 14

Abstract : Instrument modifications have made it possible to scan a 100/cm spectral region in 100 microseconds with 1/cm spectral resolution and with sample path lengths extending to 50 meters. Thus detection of transient free radicals, produced through flash photolysis, is now possible. The free radicals CF3, CCl3, and CH3 have been detected, all in the gas phase, using infrared spectroscopy, for the first time. The kinetics of the CF3 + CF3 to C2F6 reaction have been studied and a small activation energy is revealed. Five types of chemical reactions have been shown to give infrared laser emission with thirty-two different examples. The types are: Three body reactions; Abstraction reactions; Elimination reactions; Photoelimination reactions; and Photodissociation reactions. By examining the relative gain of the various rotation-vibration transitions, the rate constant ratio can be measured, k(v)/k(v-1). Through the principle of microscopic reversibility, these ratios are clarifying the role of vibrational degrees of freedom in chemical reaction rates. (Author)

Descriptors :   (*INFRARED SPECTRA, *FREE RADICALS), (*GAS LASERS, CHEMICAL REACTIONS), RESOLUTION, ELIMINATION REACTIONS, PHOTOCHEMICAL REACTIONS, DISSOCIATION, HALOGENATED HYDROCARBONS, FLUORINE COMPOUNDS, INFRARED LASERS

Subject Categories : Lasers and Masers
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE