Nonequilibrium photochemical reactions induced by lasers. Technical progress report

Technical Report · Mon Jan 15 04:00:00 EST 1979

OSTI ID:6137028

Steinfeld, J I

Infrared double resonance spectroscopy was carried out on SF/sub 6/ molecules excited with a CO/sub 2/ laser, using a tunable diode laser as the probe source. Power broadening induced by the pump beam, transitions in the ..nu../sub 3/ ..-->.. 2..nu../sub 3/ manifold, and relaxations within the ..nu../sub 3/ vibrational level brought about by collisions between SF/sub 6/ and other molecules of SF/sub 6/, He, and CH/sub 3/F were observed. Results indicate that rotational broadening of the excited-state absorption band envelopes may play a significant role in anharmonicity compensation, and that rotational relaxation proceeds mainly by collisions which reorient the angular momentum with respect to the internal coordinates of the SF/sub 6/ molecule, but leave the total J quantum number nearly unchanged. Progress is also reported in the study of reactions induced by multiple infrared photon excitation. The dehydrohalogenation of R/sub 2/ C = CHCl systems (R = H, CH/sub 3/, F) has been examined for the vinyl carbene (R/sub 2/ C = C:) intermediate. Several theoretical aspects of the problem have been examined, including the effect of using various distribution functions in RRKM models of the multiphoton dissociation process, and an analysis of energy deposition in absorbing samples by focused Gaussian beams.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Chemistry
• OSTI ID: 6137028
• Report Number(s): MIT-2793
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
CHEMICAL REACTIONS
DISSOCIATION
DOUBLE RESONANCE METHODS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY LEVELS
EXCITED STATES
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
INFRARED SPECTRA
LASER RADIATION
MASSLESS PARTICLES
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTONS
RADIATIONS
RELAXATION
RESEARCH PROGRAMS
ROTATIONAL STATES
SPECTRA
SPECTROSCOPY
SULFUR COMPOUNDS
SULFUR FLUORIDES
VIBRATIONAL STATES