G3(MP2) Ring Strain in Bicyclic Phosphorus Heterocycles and Their Hydrocarbon Analogues
Bibliographic record
Abstract
[Figure: see text] The ring strain present in 2-aza-1-phosphabicyclo[n.1.0]alka(e)nes (n = 1-5) is calculated at the G3(MP2) level using homodesmotic reactions. The influence of cyclopropa(e)nation and heteroatom substitution is analyzed by a comparison with the corresponding bicyclic hydrocarbons and separate ring systems. It is shown that the strain caused by fusion with a cyclopropane is the sum of the separate rings, whereas the strain resulting from fusion with cyclopropene leads to strain energies much larger than the sum of rings, as a result of the inverted nature of the bridgehead carbon. In all ring structures but one, cyclohexane, substitution by nitrogen and phosphorus is favorable and the effect is most pronounced for the most condensed structures. The calculated strain energies correlate very well with the experimental stability and reactivity of the bicyclic iron-amino phosphirane and phosphirene complexes.
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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) | 0.003 | 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".