Accession Number:

ADA160131

Title:

Spectroscopy and Energy Transfer Kinetics of the Interhalogens.

Descriptive Note:

Final rept. Apr 83-Mar 84,

Corporate Author:

ILLINOIS INST OF TECH CHICAGO

Personal Author(s):

Report Date:

1984-03-01

Pagination or Media Count:

39.0

Abstract:

The electronic quenching of Br2 B by Br2 x and He was investigated in the gas phase. Non-linear self quenching plots revealed the presence of rapid energy transfer to predissociated levels. Quenching and rotational energy transfer rates of 4.2 x 10 to the 10th power and approx. 8 x 10 to the -10th power ccmolecules respectively were obtained by kinetic modeling. Near-resonant vibrational energy transfer also contributes to the deactivation process, and this occurs wtih a rate constant 3.5 x 10 to the 10th power ccmolecules. Electronic quenching of Br2 B by He was found to be slow k sub q 2 x 10 to the 12th power ccmolecules, but deactivation by rapid rotational and vibrational energy transfer k sub t 10 to the -10 power ccmolecules was observed. Gas phase electronic quenching of I2 B by He at 9.4K was studied in a free jet expansion. An effective cross section of 0.33 sq A was obtained, demonstrating a significant collision energy dependence for this parameter. Simple trajectory calculations show that this result is compatible with a collision induced predissociation model of the deactivation process. The HeBr2 Van der Waals complex was observed in a free jet expansion. The complex was detected by laser excitation of the bands associated wtih the Br2B - X system. Excitation spectra and polarization measurements provided insights into the excitation and relaxation mechanisms present in the matrix.

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE