Welcome

The Bull Research Group is active in Physical Chemistry at the University of East Anglia (UEA). Our work focuses on the excited-state dynamics of isolated molecules, studied using state-of-the-art, custom-built vacuum instrumentation. We have a particular emphasis on isomers and photoisomerisation, and perform electronic structure calculations and non-adiabatic molecular dynamics to help understand the gas-phase dynamics. Our distinctive strength lies in designing and building our own experimental instrumentation, including the associated electronics, control software, and data-processing workflows, alongside complementary theoretical calculations.

Our research techniques include tandem ion mobility spectrometry to isomer- or “shape”-select target ions, quadrupole or time-of-flight mass spectrometry to mass-select target ions, photoelectron velocity-map imaging to probe the target anions, and condensed phase ultrafast experiemnts to probe the influence of an environment. Our experiments are configured so that laser light can be introduced at various points in each of our experiments, allowing maximum flexibility in experimental design, including to photogenerate, separate, and then probe short-lived photoisomers (e.g. intermediates in photocycles).

Our research interests centre on isomer-specific spectroscopy and molecular dynamics across a wide range of systems, including geometric isomers, tautomers, deprotomers, and distinct cluster structures. Current targets include anionic biochromophores, such as the chromophore of green fluorescent protein (GFP) and related systems including cyan and Kaede fluorescent proteins, as well as hydroxycinnamates, flavins, and conjugated polyenes. We are also actively investigating photomolecular motors and photoswitches based on azobenzenes, stilbenes, and ring-opening/closing reactions. Systems with multiple isomeric or photoswitchable states are of particular interest.