σ→σ* Transitions in Mn2(CO)8L2 complexes (L = P-donor ligands): π-acidity and oxygen pendant group effects in phosphite ligands
Bibliographic record
Abstract
Comparison of the energies assigned to the sigma-->sigma* transitions in bis-axial Mn2(CO)8L2 complexes when L = phosphites and phosphinites with those when L = alkyl and aryl phosphines shows that the oxygen-containing ligands do show effects associated with their pi-acidity. However, the data also strongly suggest that the energies are affected by the presence of the oxygen atoms themselves to an extent that increases linearly with the number of oxygen atoms connected to the P-donor atoms. This "oxygen effect" is analogous to, but distinct from, the aryl effect that is also simply proportional to the number of aryl groups attached to the P-donor atoms. This resolves the incongruity of the claim that phosphites also show an "aryl effect", and suggests that specific "pendant group effects" due to the nature and number of atoms attached to the phosphorus atoms of P-donor ligands (aryl, oxygen, nitrogen, sulfur etc.) may be quite general.
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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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".