High-Temperature Catalysts for the Production of α-Olefins Based on Iron(II) and Cobalt(II) Tridentate Bis(imino)pyridine Complexes with a Double Pattern of Substitution: <i>o</i>-Methyl plus <i>o</i>-Fluorine in the Same Imino Arm
Bibliographic record
Abstract
The new series of bis(imino)pyridine ligands [2-F-6-MePhN═C(Me)PyC(Me)═NPh-2-F-6-Me] ( 14 ), [2-F-6-MePhN═C(Me)PyC(Me)═NPh-2-Me] ( 19 ), and [2-F-6-MePhN═C(Me)PyC(Me)═N-Ph-2,4-Me 2 ] ( 20 ) and their corresponding Fe(II) complexes [{2-F-6-Me-PhN═C(Me)PyC(Me)═NPh-2-F-6-Me}FeCl 2 ] ( 4 ), [{2-F-6-MePhN═C(Me)PyC(Me)═NPh-2-Me}FeCl 2 ] ( 5 ), and {[2-F-6-MePhN═C(Me)PyC(Me)═NPh-2,4-Me 2 ]FeCl 2 } ( 6 ) and Co(II) complex [{2-F-6-MePhN═C(Me)PyC(Me)═NPh-2-Me}CoI 2 ] ( 7 ) with a double pattern of substitution, o -methyl plus o -fluorine in the same imino arm, were synthesized and fully characterized. According to X-ray analysis 4, 5, and 7 exist mostly in the unexpected “up-up” conformers in the solid state. The Co−N bonds in 7 are shorter than the corresponding Fe−N bonds in the analogous complex 5 by 0.003−0.025 Å. This shortening of metal−N bonds going from iron(II) to cobalt(II) complexes can be explained by the smaller van der Waals radius of Co vs. that of Fe. The Fe complexes 4 – 6 afforded very productive catalysts for the production of α-olefins with a more linear Schultz−Flory distribution of α-olefins and with higher K values than the parent methyl-substituted Fe(II) complex [{2-MePhN═C(Me)PyC(Me)═NPh-2-Me}FeCl 2 ] ( 1 ). The cobalt complex 7 was found to have very low activity in α-olefin oligomerization experiments within the tested range of temperatures (60–130 °C).
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".