Investigation of the mechanism of 1,2-migrations in methoxysiloxycarbene with the electron localization function
Bibliographic record
Abstract
A topological analysis of the gradient vector field of the electron localization function (ELF) has been used to investigate the mechanism of 1,2-silyl migration from oxygen to the carbene carbon in methoxysiloxycarbene.As well, the analogous 1,2-methyl migration was investigated for comparison.Plots of ELF isosurfaces and contour maps clearly reveal that the monosynaptic valence basin corresponding to the carbene lone pair becomes the disynaptic valence basin corresponding to the developing carbon-silicon bond in the transition state for 1,2-silyl migration, while it remains effectively unaltered in the transition state for 1,2-methyl migration.These results suggest that 1,2-silyl migration proceeds via nucleophilic attack by the carbene lone pair at silicon, whereas the energetically unfavorable 1,2-methyl migration appears to involve an anion-like shift from oxygen to the carbene center, in good agreement with previous findings.
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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 | 0.000 | 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) | 0.001 | 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".