Palladium catalyzed homocoupling reactions of gem-dibromo BODIPYs: Formation of dimer and trimer products
Bibliographic record
Abstract
We report on the synthesis and spectral properties of BODIPY 1,3-diyne dimers and 1,1-diynyl-1-alkene trimers, prepared via the Pd-catalyzed homocoupling reaction of a series of gem -dibromovinyl BODIPY (1,1-dibromo-1-alkene 4,4-difluoro-5-aryl-4-bora-3a,4a-diaza- s -indacene) dyes. The dimer and trimer moieties are connected through the ethynyl bond, attached at p - meso -phenyl or β-positions of the pyrrole ring, directly or through the phenyl spacer ring at the β-position. The assigned molecular structures of the products were confirmed using MS, 1 H, 13 C, 9 F NMR and 11 B NMR spectroscopic techniques. The absorption, fluorescence and solvatochromic properties were investigated in different solvents. The absorption maxima of unsubstituted pyrrole derivatives are bathochromic shifted as compared to the tetramethyl pyrrole substituted analogs. The highest absorption maxima were obtained when unsubstituted pyrrole 1,1-diynyl-1-alkene trimers featured a phenyl ring at the β-position. Dimers do fluoresce while trimers are void of fluorescence properties. • Gem -dibromovinyl BODIPY. • Covalently linked BODIPY dimers and trimers were synthesized. • The BODIPY units were connected at meso-meso and β − β positions. • Meso-Meso BODIPY conjugates exhibit stronger fluorescence than the β − β BODIPY dyad conjugates. • Solvatochromism.
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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".