Electron scattering on stored mononucleotide anions

Collisions between electrons and deprotonated mononucleotides, AMP and UMP, were studied at the electrostatic storage ring ELISA where the two anions were stored with a 1/e lifetime of 13.5 s. It is found that the threshold energy for electron-induced reactions leading to production of neutral fragments is as high as about 12 eV for both species. The high threshold is explained within the context of a classical reaction model, applicable for atomic anions, and a high electron-binding energy of about 5 eV for the two mononucleotides. There is no evidence in the cross sections for formation of short-lived doubly charged anions.