Dynamics of Anions Probed by
Photoelectron Imaging

Abstract

This work comprises of the design and construction of a novel ion trap and guide
system for the existing photoelectron spectrometer along with the study of two
molecular systems.
The redesigning of the system was to address shortcomings in the previous design
and to open the door to new possibilities of research. The new components have
been installed and proof-of-concept data has been taken that shows the success of
the new cryogenic cooling system upon the ions.
The anionic resonances of anthracene, a polyaromatic hydrocarbon (PAH), were
studied using the new apparatus. This allowed for the use of a new methodology to
produce ions of interest that were previously impossible to study. While we found
that photodissociation gave better regioselectivity, it was possible to generate the
most stable deprotonated from of the anthracenyl anion. Considering the formation
of the anions in the interstellar medium, it was shown that it is likely that the
anthracenyl resonances preferred to decay by autodetachment. This would result in
little formation of the anion from the approach of an electron upon the neutral.
The chromophore of the Green Fluorescent Protein (GFP) has been extensively
studied by other researchers. We investigated the dynamics of an isomer of that
chromophore. The movement of a single functional group from the para- to the
meta- position completely alters the energetics of the system along with the
dynamics. It was shown that this structural change would make for a significantly
poorer choice as a chromophore for a fluorescent protein.