Selected projects in gas-phase spectroscopy

Abstract

Three projects have been carried out in the area of gas-phase spectroscopy: i. The infrared emission spectra of the transient molecules HBO and DBO have been obtained with a Fourier transform spectrometer. The rotational-vibrational transitions were recorded at a resolution of 0.01 cm^-1 over the wavenumber range between 350 and 4000 cm^-1. The line positions have been measured and analyzed. ii. The infrared spectra of gas-phase uracil, thymine, and adenine have been recorded from 100 to 3700 cm^-1 at a resolution of 1 cm^-1. The vibrational band positions and qualitative band intensities are reported and compared to published matrix data and to theoretical calculations. The work suggests that gas-phase emission spectroscopy is a sensitive technique for recording the spectra of organic and biological molecules. iii. The ionization potentials of neutral osmium and iridium atoms have been obtained by mass-analyzed optical-optical double resonance spectroscopy. Observation of the photoionization thresholds have yielded approximate values of 68058+_2 cm^-1 for Os 1 and 72324+_2 cm^-1 for Ir 1. In addition, high-lying ns and nd Rydberg series have been recorded and fit to a standard expression in order to obtain independent estimates of the ionization potentials. The results are 68058.9+_1.6 cm^-1 for Os 1 and 72323.9+_1.8 cm^-1 for Ir 1.