Relaxation of green fluorescent protein chromophore anion observed by photodissociation in an electrostatic storage ring

The gas-phase absorption properties of the green fluorescent protein chromophore anion were studied using an electrostatic storage ring. The time sequence of neutral particles produced by photodissociation was detected following laser irradiation. The lifetimes of the photo-absorbed ions depended on their storage time in an ion trap before injection into the storage ring. The lifetime increased with the storage time and saturated, indicating a change in the population of rovibrationally excited states with respect to the storage time. Photodissociation neutral spectrum of the relaxed ions measured as a function of the laser wavelength was characterized by a narrow asymmetric shape, which was in good agreement with the photo fragment ion action spectrum reported recently.