Probing the Electronic Structure and Dynamics of Anions in the Gas Phase

Abstract

The electronic structure and dynamics of a number of anions in the gas phase have been investigated through joint experimental and computational methods. Photoelectron imaging was used to obtain both frequency-, time- and angle-resolved photoelectron spectra. Quantum chemistry calculations modelled different experimental parameters and provided insight into the complex photoelectron signatures observed. A particular emphasis on advancing the understanding and interpretation of the photoelectron angular distributions in both the frequency- and time-domain was made.
The need for caution and understanding of the considerations one needs to make, and the requirement to be flexible with the theoretical model used to interpret a specific problem are presented. This was emphasized throughout the results section, where the complexity of models required ranged from a simple Hückel model to a multi-configurational multi-reference model. An analysis of the sensitivity of the parameters used in the calculation of photoelectron angular distributions with the Dyson orbital approach was presented.
The results were presented within three broad themes. Section A presented results in which the photoelectron angular distributions were modelled and interpreted to give novel insight into the character and structure of the molecular anions investigated. Analysis of the photoelectron angular distributions was presented both in the frequency- and time-domain. Section B presented studies in which the ‘bottom-up’ approach was used to elucidate information on the structure-function dynamics of small components of more complex systems. Finally, Section C presented results in which the prevalence and importance of non-valence states were probed.