Laser induced fluorescence studies in the gas phase
Laser Induced Fluorescence has been used to study rotational and vibrational energy disposal following gas phase photodissociations and reactions of small molecules. Three distinct systems have been studied. The rotational and vibrational distributions in the ground and first electronically excited states of the OH radical have been studied following the two and three photon dissociation of water using laser radiation of 266nm and 355nm wavelength respectively. The results have been compared to recent theoretical calculations and experimental investigations at different wavelengths in the same region of the spectrum. The rotational distribution in vibrational levels of the ground electronic state of the NO molecule following 355nm photodissociation of methyl nitrite have been studied and compared to recent experimental studies of the photodissociation of NO containing molecules. A statistical treatment allowed the vibrational distribution to be determined. A simple model is described which rationalises the process. Finally, the rotational distributions within vibrational levels of the ground electronic state of the CO molecule, produced via the gas phase reaction between oxygen atoms and the CS radical, are presented. The vibrational distribution resulting from this reaction is well established but, to date, there have been no reports of the rotational distribution. A proposal has been made to employ the system studied in a vacuum ultra violet laser. Some comments are made concerning this proposal.