Orientation Effect in the Low‐Energy Electron Attachment to the Apolar Carbon Tetrafluoride Molecule

Abstract

Beim Einfangen von Elektronen mit einem antibindenden Kohlenstoff‐Fluor‐σ*‐Orbital werden nach Anlagerung des Elektrons an CF4 Vektorkorrelationen der Fragmente F− und CF3 bzw. F und CF3− für zwei komplementären Dissoziationspfade erhalten. Ein Orientierungseffekt bei der Elektronenanlagerung wird mit Geschwindigkeitsbildgebung beobachtet (siehe Bild).

Two- and Three-Body Dissociation Dynamics of Temporary Negative Ion NF3–

“…For NH 3 – , the two-body dissociation to H – and NH 2 – exhibited the forward (H – ) and backward (NH 2 – ) distributions, implying a molecular orientation effect in the DEA process . The molecular orientation effect was observed more clearly in another study of the DEA to CF 4 . However, this phenomenon is not present for NF 3 , perhaps due to the different shapes of the related orbitals: 1e (NH 3 , see figure 8b in ref ) and 5e (NF 3 , see figure ).…”

“…The effective width of this time-gate pulse was ∼45 ns, which was acceptable for slicing the Newton sphere of the F – ion with the time-of-flight spread of ∼430 ns. The kinetic energies derived from the image have been calibrated with the experimental data available in the literature. ,− …”

“…6 The molecular orientation effect was observed more clearly in another study of the DEA to CF . 18 However, this phenomenon is not present for NF 3 , perhaps due to the different shapes of the related orbitals: 1e (NH 3 , see figure 8b in ref 6) and 5e (NF 3 , see figure 5). The unsatisfied experimental data fittings using p + d (E) for the angular distributions of H − and NH 2 − reminded the authors that the Jahn−Teller effect or nonadiabatic effect should be considered.…”

Photo-induced degradation of PFASs: Excited-state mechanisms from real-time time-dependent density functional theory

“…This general dissociation mechanism is also similar to that observed in highresolution gas-phase electron-collision experiments in which electron attachment to a CF4 molecule also leads to C-F bond dissociation. 28 However, the major difference is that electrons in these prior experiments were artificially produced with an electron beam/gun, whereas the source of electrons in our solvated PFAS system naturally arises from nearby water molecules that are dynamically excited with an optical pulse. Finally, it is worth mentioning that our approach highlights the importance of utilizing these RT-TDDFT techniques for probing excited-state, photo-induced degradation of PFAS contaminants, which have started to garner immense attention in the scientific community.…”

Complex basis functions revisited: Implementation with applications to carbon tetrafluoride and aromatic N-containing heterocycles within the static-exchange approximation

“…More recently, CF 4 has been the subject of some studies of orientation effects in dissociative electron attachment processes that may proceed through these resonances. 54,55 The resonance energies of the two lowest shape resonances of CF 4 (C-F = 1.33 Å) are reported in Table V along with other calculations from the literature. The complex basis function results show the T 2 resonance position to be lower in energy than that of the A 1 resonance which is in agreement with most of the previous theoretical and experimental results.…”