<i>Rac/</i><i>m</i><i>eso</i> Transformations of Disiloxane-bis(1-indenyl)-<i>a</i><i>nsa</i>-ferrocenes: An X-ray Crystallographic and NMR Study
Bibliographic record
Abstract
Both stereoisomers of disiloxane-bis(1-indenyl)- ansa -ferrocene, Fe(η 5 -inden-1-yl-SiMe 2 ) 2 O, 1, were prepared by the reaction of disiloxane-bis-1,3-inden-1‘-yl anion with FeCl 2; the diastereomers were separated by column chromatography and recrystallized from n -heptane. A single-crystal X-ray diffraction study confirmed that each stereoisomer, racemic 1 r and meso 1 m, involves parallel bis-indenyl coordination to the Fe metal center. These isomers were also characterized by 1 H, 13 C, and 29 Si NMR and IR spectroscopy. Compounds 1 r and 1 m could each be transformed into the other diastereomer: the conversion was retarded by base, but accelerated under weakly acidic conditions. The mechanism of this process, investigated using deuterium labeling experiments, is consistent with a series of successive 1,5-suprafacial, sigmatropic silicon shifts. Compound 1 was also copolymerized with 1,1,3,3,5,5,7,7-octamethylcyclotetrasiloxane (D 4 ) and 1,1,1,3,3,5,5,5-octamethyltrisiloxane (MDM) to produce green organometallic polymers.
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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) | 0.002 | 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".