Nitro‐substituted iron(II) tridentate bis(imino)pyridine complexes as high‐temperature catalysts for the production of α‐olefins
Bibliographic record
Abstract
Abstract A new series of nitro‐substituted bis(imino)pyridine ligands {2,6‐bis[1‐(2‐methyl‐4‐nitrophenylimino)ethyl]pyridine, 2,6‐bis[1‐(4‐nitrophenylimino)ethyl]pyridine, (1‐{6‐[1‐(4‐nitro‐phenylimino)‐ethyl]‐pyridin‐2‐yl}‐ethylidene)‐(2,4,6‐trimethyl‐phenyl)‐amine, and 2,6‐bis[1‐(2‐methyl‐3‐nitrophenylimino)ethyl]pyridine} and their corresponding Fe(II) complexes [{p‐NO2o‐MePhNC(Me)PyC(Me)NPho‐ Mep‐NO2}FeCl2 (10), L2FeCl2 (11), {m‐NO2o‐MePhNC(Me)PyC(Me)NPho‐Mem‐NO2}FeCl2 (12), and {p‐NO2PhNC(Me)PyC(Me)NMes}FeCl2 (14)] were synthesized. According to X‐ray analysis, there were shortenings of the axial FeN bond lengths (up to 0.014 Å) in para‐nitro‐substituted complex 10 and (up to 0.015 Å) in meta‐nitro‐substituted complex 12 versus the Fe(II) complex without nitro groups [{o‐MePhNC(Me)PyC(Me)NPho‐Me}FeCl2 (1)]. Complexes 10, 12, and 14 afforded very active catalysts for the production of α‐olefins and were more temperature‐stable and had longer lifetimes than parent non‐nitro‐substituted Fe(II) complex 1. The reaction between FeCl2 and a sterically less hindered ligand [p‐NO2PhNC(Me)PyC(Me)NPhp‐NO2] resulted in the formation of octahedral complex 11. A para‐dialkylamino‐substituted bis(imino)pyridine ligand [p‐NEt2o‐MePhNC(Me)PyC(Me)NPho‐Mep‐NEt2] and the corresponding Fe(II) complex [{p‐NEt2o‐MePhNC(Me)PyC(Me)NPho‐Mep‐NEt2}FeCl2 (16)] were synthesized to evaluate the effect of enhanced electron donation of the ligand on the catalytic performance. According to X‐ray analysis, there was a shortening (up to 0.043 Å) of the axial FeN bond lengths in para‐diethylamino‐substituted complex 16 in comparison with parent Fe(II) complex 1. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2615–2635, 2006
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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".