Pyrene Derivatives of 2,2′-Bipyridine as Models for Asphaltenes: Synthesis, Characterization, and Supramolecular Organization
Bibliographic record
Abstract
The behavior of 4,4′-bis-(2-pyren-1-yl-ethyl)-[2,2′]bipyridinyl (PBP) was studied as a model for petroleum asphaltenes with a bridged structure. PBP consists of two pyrene groups bridged by a bipyridyl spacer, and exhibits similar solubility and chromatographic properties to some fractions of asphaltenes. On the basis of nuclear magnetic resonance, steady state fluorescence, vapor pressure osmometry, solubility, and adsorption behavior studies, PBP gave self-association in solution. On the basis of these data and single crystal X-ray analysis, this behavior was attributed to π–π stacking interactions involving both pyrene rings and the bipyridine spacer. These results demonstrate that bridged aromatic species with up to four fused aromatic rings are capable of self-association in solution.
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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".