Dissociative electron attachment to β-alanine.

A detailed study on dissociative electron attachment (DEA) to β-alanine (βA) in the gas phase is presented. Ion yields as a function of the incident electron energy from about 0 to 15 eV have been measured for most of the fragments. As for all α-amino acids, the main reaction corresponds to the loss of a hydrogen atom, although many other fragments have been observed that involved more complex bond cleavages. Threshold energies have been calculated by using the G4(MP2) method for various decomposition reactions. Fragmentation pathways were also investigated to measure metastable decays of the intermediate fragment anion (βA-H)(-) by using the mass-analyzed ion kinetic energy (MIKE) scan technique. Comparisons with α-alanine and other amino acids are made when relevant.