Effect of Cross-Conjugation on Derivatives of Benzoisoindigo, an Isoindigo Analogue with an Extended π-System
Bibliographic record
Abstract
The effect of cross-conjugation on small molecule organic semiconductors derived from benzoisoindigo, a ring-expanded isoindigo derivative, is reported. In this work, 5-hexyl-2,2′-bithiophene was substituted at the cross-conjugated 5,5′-position of benzoisoindigo, yielding a new organic semiconductor with a donor–acceptor structure. The optoelectronic properties of this benzoisoindigo derivative were studied and compared with those of both linearly conjugated and cross-conjugated isoindigo-based analogues. Extending the conjugation of the electron-deficient isoindigo through ring fusion did substantially red-shift the absorption maximum of the highest occupied molecular orbital to lowest unoccupied molecular orbital transition; however, the cross-conjugation significantly reduced the oscillator strength. As a result, the photocurrent was significantly lower for organic photovoltaic devices made with cross-conjugated materials. This suggests that if synthetic methods to access the linearly conjugated 7,7′-derivatives can be developed, benzoisoindigo may be able to serve as a useful electron-deficient subunit in donor–acceptor systems.
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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".