Molecular ions act as chromophores in a variety of proteins and they serve important purposes for example 

in energy harvesting and vision. Typically, protein interactions change the absorption wavelength (color 

tuning) as well as the speed and quantum yields of the molecular response of the chromophore. To have a 

reference for such interactions, we study the absorption properties as well as the molecular response times 

in vacuum, i.e. in an environment devoid of external perturbations (for example charges, dipoles and 

hydrogen bonding). In recent measurements with anionic chromophores we see signatures of electronically 

excited states, energetically far above the electron-detachment threshold. Perspectives for using UV 

radiation from ASTRID II together with a new electrostatic storage ring will be discussed.