Laser study of the photophysical properties of UF₆

Abstract

The purpose of this paper is to review the most relevant theoretical and experimental results reported in recent years, on the photophysical properties of the uranium hexafluoride molecule in the gas phase. Details of the structure of the molecular orbitals of UF₆ are discussed with reference to theoretical calculations of the electronic states. Tentative assignments of the electronic transitions in the experimental visible-uv absorption spectrum are also considered. The fluorescence properties of the excited states of UF₆ are critically reviewed. The use of laser beams to excite the fluorescence emission of UF₆ is shown to be a fruitful experimental technique. The measurement of fluorescence parameters (i.e. the emission and excitation spectra, the decay time and quantum yield) is a particularly valuable and sensitive way of studying the dynamics and structure of the excited electronic states. The different mechanisms of fluorescence quenching that have been proposed are also critically reviewed.