Dissociative electron attachment to formic acid (HCOOH)

Dissociative electron attachment to formic acid as a fundamental center in enzymatic activity is studied. A prominent resonance is observed peaking at 1.25 eV which decomposes into the formate anion HCOO− and a hydrogen radical. Resonances at higher energy are associated with O− and OH− formation on a considerably smaller intensity scale. On the basis of high level ab initio calculations, the low energy feature arises from different closely spaced single particle shape resonances with no specific valence character. The HCOO− ion yield carries structure which is tentatively ascribed to vibrational excitation in the formate anion.