Dynamics of Dissociative Electron–Molecule Interactions in Condensed Methanol
Bibliographic record
Abstract
We have investigated the dynamics of low-energy (1–20 eV) electron-induced reactions in condensed thin films of methanol (CH 3 OH) through both electron-stimulated desorption (ESD) and postirradiation temperature-programmed desorption (TPD) experiments conducted under ultrahigh vacuum conditions. Results of ESD experiments, involving a high-sensitivity time-of-flight mass spectrometer, indicate that anion (H –, CH –, CH 2 –, CH 3 –, O –, OH –, and CH 3 O – ) desorption from the methanol thin film at incident electron energies below about 15 eV is dominated by processes initiated by the dissociation of temporary negative ions of methanol formed via electron capture, a resonant process known as dissociative electron attachment (DEA). However, postirradiation TPD investigation of radicals, especially •CH 2 OH and CH 3 O• remaining in the methanol thin film, demonstrates that electron impact excitation, not DEA, is the primary mechanism by which the radical–radical reaction products methoxymethanol (CH 3 OCH 2 OH) and ethylene glycol (HOCH 2 CH 2 OH) are formed. This apparent dichotomy between the results of ESD and postirradiation experiments is attributed to the low DEA cross section for methanol compared to that of species such as halomethanes. Our results suggest that for molecules such as methanol, low-energy electron-induced electronic excitation, rather than DEA, plays a dominant role in ionizing radiation-induced chemical synthesis in environments such as the interstellar medium.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".