Study of Negative Ion Formations by Electron Impact I. Negative Ions Produced from Acrylonitrile

Theoretical Investigation of Dissociative Electron Attachment of Acrylonitrile

“…According to Tsuda et al, CN – formation consists of three processes, the first process (eq ) appears below 2.0 eV, which is close to the present peak at 1.5 eV. The same feature is also observed by Heni and Illenberger at 2.0 eV, while this peak is missing in the reported data of Sugiura et al as they collected the ion current beyond 3 eV. According to Tsuda et al, the feature observed by us at 1.5 eV may be due to the electron capture reaction given as normalC 2 normalH 3 normalC normalN + e − → normalC normalN − + normalC 2 normalH 3 .25em ( A P c a l = 1.3 e V ) The above AP cal is calculated using Δ H f (C 2 H 3 CN) = 2.0 eV, Δ H f (CN – ) = 0.47 eV, and Δ H f (C 2 H 3 ) = 2.83 eV .…”

“…We have performed DEA calculations of acrylonitrile for energies below 20 eV. According to the literature survey, − there are multiple dissociative channels possible in acrylonitrile of which the most abundant are CN – and C 3 N – . We have considered these two channels for the present study.…”

“…The reason for the appearance of CN – at such a low energy is mainly the high electron affinity of CN. Sugiura et al and Heni and Illenberger have provided ion yield (current) curves, and in order to compare present appearance energy, we have extracted their values from the starting point of the curve, while Tsuda et al have given their appearance energy in the curve itself. We have also extracted the peak values of the ion yield current for all three measurements as they have not been listed separately.…”

“…The second resonant process in Figure starts appearing at 3.6 eV, and its peak is observed at 4.5 eV; the possible reaction for this resonant process is given below normalC 2 normalH 3 normalC normalN + e − → normalC normalN − + normalC 2 normalH 2 + normalH .25em ( A P c a l = 3.08 e V ) In this case, AP cal is calculated using Δ H f (C 2 H 2 ) = 2.35 eV and Δ H f (H) = 2.26 eV . Thus, the present AP of 3.6 eV is close to 3.50 eV reported by Sugiura et al and 3.8 eV seen in Heni and Illenberger’s ion yield curve but slightly higher than the value of 3 eV reported by Tsuda et al The present second peak at 4.5 eV is exactly the same as the 4.5 eV peak of Heni and Illenberger and lower compared to 4.9 eV and 5.1 eV extracted from the ion yield curves of Sugiura et al . and Tsuda et al, respectively.…”

“…According to the literature survey, there are only three experimental studies − on the negative ions formed in acrylonitrile, and they have been reported many decades ago. On the theoretical front, there is no work on DEA of this molecule reported yet.…”