Resonant electron trapping and photoelectron spectroscopy for substituted fluorinated nitrobenzenes

Dissociative electron attachment to fluorinated nitrobenzenes

“…In contrast, studies on fluorinated nitrobenzenes, especially difluoronitrobenzene (DFNB) isomers, tetrafluoronitrobenzene (4FNB) isomers and pentafluoronitorbenzene (5FNB) are scarce. In the electron attachment experiments of Burmistrov et al, the formation of parent anions (M -) for 2,5-DFNB, with considerably lower intensity also for 4FNB and a very weak parent ion signal for the fully fluorinated nitrobenzene close to the detection limit of the experiment were reported [18]. For DFNB and 4FNB a variety of fragment ions were found; the most abundant fragments were (M-NO2) -, NO2and (M-NO-HF) -.…”

“…In the case of 2,5-DFNB it was reported that the parent anion is also formed at 0 eV electron energy [18]. Previous studies on electron attachment to nitrobenzene [14] and all three isomers of singly fluorinated nitrobenzene [20] reported parent anion formation also at 0 eV electron energy.…”

“…Two further ions at higher masses could be identified non-ambiguously, namely (M-NO-HF)and (M-NO2-HF) -. In the work of Burmistrov et al [18], the formation of (M-NO-HF)was reported upon electron attachment to 2,5-DFNB with a resonance maxima at 3.7 eV. The formation of (M-NO2-HF)was observed for 2,5-DFNB at electron energies of 4.0 eV and for 4FNB (tetrafluoronitrobenzene isomers) at 3.5 eV.…”

“…Previous studies on electron attachment to nitrobenzene [14] and all three isomers of singly fluorinated nitrobenzene [20] reported parent anion formation also at 0 eV electron energy. On the other hand, the fully fluorinated nitrobenzene C 5F5NO2 forms parent anions only very weakly [18] and it was also reported that it exclusively undergoes DEA [19]. Given that singly fluorinated, triply fluorinated nitrobenzenes and the doubly fluorinated 2,5-DFNB molecule all show parent ion peaks at 0 eV, the higher position of the maxima of the parent anion efficiency curve of 3,5-DFNB cannot be directly related to the addition of fluorine atoms.…”

“…For DFNB and 4FNB a variety of fragment ions were found; the most abundant fragments were (M-NO2) -, NO2and (M-NO-HF) -. It turned out that the substitution of hydrogen by fluorine leads to a shift of the respective resonances to lower energies [18]. In contrast, Langer et al reported fragment anion formation via DEA exclusively for 5FNB [19].…”