A computational study of the threshold energies of the 1,2-FCl interchange reaction of chlorofluoroethanes
Bibliographic record
Abstract
The 1,2-FCl rearrangement reaction of a series of haloethanes is investigated by comparisons of the optimized ground- and transition-state geometries. Investigation of the effect of level of theory and basis set shows that the trends in threshold energies for rearrangement are reproduced across all levels of theory and basis set, and hence that a moderate level of theory and basis set is adequate for investigating the important trends in this reaction. Threshold barriers increase when a large number of fluorine atoms are attached to the carbon atom bearing the interchanging fluorine, suggesting that the C–F bonds prove difficult to distort to the transition geometry; the increase is smaller for fluorine substitution on the carbon atom bearing the interchanging hydrogen atom. By considering sets of isomeric reactions, the barrier height is shown to closely follow the thermodynamic stability of the alkane undergoing rearrangement; however there is a secondary effect owing to the relative stability of the transition geometry. This relative stability can be related to the thermodynamic stability of a series of isomeric alkenes that resemble the transition geometry without the rearranging atoms. This series of molecules constitute an unusual set owing to the ability to consider these three contributions to the activation barrier separately.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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 source (direct Gemma or distilled Codex), 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".