Synthesis, structure–properties of planar, end-substituted, light-emitting oligophenylenevinylenes
Bibliographic record
Abstract
A novel homologous series of highly soluble, multiple alkoxy end-substituted oligophenylenevinylenes (OPV) containing up to six phenyl rings were synthesized. In contrast to the lateral substituted OPVs, our theoretical and experimental evidences have shown that the electron donating groups incorporated at the ends of an oligomer do not affect co-planarity of the π-conjugated system. They can also promote a faster convergence of the HOMO–LUMO energy gap relative to those of unsubstituted OPVs suggesting a shorter effective conjugation length in this series. These end-substituted OPVs containing more than three phenyl-rings exhibit very high fluorescence quantum yields (more than 74%). Multi-layer LEDs using these end-substituted OPVs as emissive layers were fabricated and investigated. We have found that there is a bathochromic shift of the PL and EL maxima with an increase of chain length in this series. All these oligomer-based multi-layer LEDs show very low turn-on-voltage. In addition, the higher homologues of these oligomers suffered from severe interchain interaction leading to a dramatic decrease in the external quantum efficiency; however, this can be alleviated by doping the oligomer into the host matrix.
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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) | 0.000 | 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 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".