Journal of Physical Chemistry B, Vol.119, No.10, 3982-3987, 2015
Excited State Dynamics of the Isolated Green Fluorescent Protein Chromophore Anion Following UV Excitation
A combined frequency-, angle-, and timeresolved photoelectron spectroscopy study is used to unravel the excited state dynamics following UV excitation of the isolated anionic chromophore of the green fluorescent protein (GFP). The optically bright S-3 state, which is populated for hv > 3.7 eV, is shown to decay predominantly by internal conversion to the S-2 state that in turn autodetaches to the neutral ground state. For hv > 4.1 eV, a new and favorable autodetachment channel from the S-2 state becomes available, which leads to the formation of the neutral in an excited state. The results indicate that the UV excited state dynamics of the GFP chromophore involve a number of strongly coupled excited states.