Furoyl and thiophene carbonyl linker pyrazolyl palladium(II) complexes Synthesis, characterization, and evaluation as ethylene oligomerization catalysts
Bibliographic record
Abstract
Reactions of 2-furoyl chloride and 2-thiophene carbonyl chloride with substituted pyrazoles produced the modified pyrazolyl compounds: {(3,5-Me2pzCO)-2-C4H3O} (L1), {(3,5-Me2pzCO)-2-C4H3S} (L2), {(3,5-t-Bu2pzCO)-2-C4H3O} (L3), {(3,5-t-Bu2pzCO)-2-C4H3S} (L4), {(3,5-Ph2pzCO)-2-C4H3S} (L5), and {(pzCO)-2-C4H3O} (L6) in good yields. Reactions of these synthons with [Pd(NCMe)2Cl2] afforded the corresponding mononuclear palladium(II) complexes: [Pd(L1)2Cl2] (1), [Pd(L2)2Cl2] (2), [Pd(L3)2Cl2] (3), [Pd(L4)2Cl2] (4), [Pd(L5)2Cl2] (5), and [Pd(L6)2Cl2] (6) in moderate to high yields. All compounds synthesized were characterized by a combination of 1H NMR, 13C NMR, and IR spectroscopy. Compounds L1, 1, and 2 were examined by single crystal X-ray crystallography. DFT theoretical studies at the B3LYP/6-31+G(d) level of theory with GAUSSIAN98 have been used to rationalize some of the results. When the complexes were activated with ethylaluminium dichloride (EtAlCl2), they catalysed the oligomerization of ethylene to mostly C10 and C12 oligomers. Oligomer distribution greatly depends on the oligomerization conditions; for example, an increase in temperature and pressure produced a higher percentage of C12 compared to C10.Key words: furoyl and thiophene carbonyl linker pyrazolyl compounds, palladium complexes, ethylene oligomerization.
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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".