Resonant neutral-particle emission in collisions of electrons with protonated and sodiated nucleotide monocations in a storage ring

Abstract

Electron-ion collisions have been studied for protonated and sodiated single-strand dinucleotide monocations with various base compositions and sequences by using an electrostatic storage ring equipped with a merged-electron-beam device. The plots of neutral-particle production rates against collision energy show typical electron-capture-dissociation profiles, which are characterized by an increase in the production rate at energies close to zero and a bump at high energies. The height of the resonant bumps varies with the number of Na+ ions as well as the base composition and sequence; in most cases, the height increases with the number of Na+ ions. Molecular mechanics and semiempirical quantum-chemical calculations suggest that the rate is correlated with various base-base interactions.