Gas Phase Dissociative electron attachment study to L-Valine

Abstract

Using a crossed electron/molecule beams apparatus the dissociative electron attachment (DEA) to gas phase amino acid L‐valine has been studied. The DEA to valine at low electron energies exhibits several common features with DEA to other amino acids (glycine, alanine) and to simple organic acids. Like in the case of previously studied amino acids glycine and alanine no stable parent anion was detected. The transient negative ions is formed at low electron energies via electron capture to the unoccupied π* orbital of the COOH group, the majority of the products is associated with the COOH group. The dominant product of the DEA reaction is (Val‐H)− (m/Z=116) observed at two resonances of 1.2 eV and 5.3 eV. Other fragment anions (m/Z=100,72,56,26 and 17) are formed via the low energy resonances (below 5 eV) and core excited resonances at about 5.0 and 9.0 eV.