I. Millimeter Microwave Spectroscopy of Radicals. II. Laser Spectroscopy of the Van der Waals Molecule Ne-Cl₂

Citation

Brinza, David Edward (1984) I. Millimeter Microwave Spectroscopy of Radicals. II. Laser Spectroscopy of the Van der Waals Molecule Ne-Cl₂. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/b03t-1z96. https://resolver.caltech.edu/CaltechTHESIS:10242018-130045424

Abstract

The temperature dependence of the linewidth parameter for the pressure broadening of ClO rotational transitions was investigated. As determined from millimeter microwave spectroscopy, the value of the linewidth parameter at 218 K is 4.44±0.23 MHz/torr. The width parameter varies according to T^-0.75±0.2 over the temperature range 200-350 K. A similar study was carried out for oxygen self-broadening and broadening by nitrogen. The stronger temperature dependence for the self-broadened case suggests a resonant spin-flip or exchange process is important in the collisional broadening.

The measurement of microwave spectra of the CS radical, as produced in the ArF excimer laser photolysis (193 nm) of CS₂ was attempted. No spectra for the vibrationally excited CS molecules produced in the photolysis could be observed, presumably due to relatively slow rotational relaxation of the CS fragment.

The van der Waals molecule Ne-Cl₂ has been studied by molecular beam laser spectroscopy. Fluorescence features ~6 cm^-1 to higher energy of the Cl₂B-X band origins are attributed to Ne-Cl₂. Band shape analysis supports a T-shaped molecular structure. The metastable vibrationally excited molecule Ne-Cl₂(X¹ Σ⁺, ν" = 1) has been spectroscopically observed. The time-of-flight from the nozzle indicates the lifetime of the complex to be greater than 10^-5 sec.

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