Structural Control of Band Gap and Polaron Delocalization in 2D Azatriangulene Covalent Organic Frameworks
Bibliographic record
Abstract
New two-dimensional (2D) covalent organic frameworks (COFs) with a tri(oxa)azatriangulene (TANG) node and different polarity of the imine linkers (C=N vs N=C) and internode distance have been synthesized using a trans-imination polymerization. The orientation of the imine linker controls the donor-acceptor interactions in these π-conjugated COFs, resulting in a large modulation of the valence band maximum (–4.2 to –5.4 eV) and the band gap (Eg ≈ 1.2-1.6 eV). p-Doping of COFs in iodine vapor improves the -conjugation and results in the formation of highly delocalized polarons with an absorption band extending into the far-infrared (THz band) region. Reducing the TANG-TANG internodal distance increases the 2D band-width dispersion; upon doping, the corresponding COF shows the highest (in the series) electrical conductivity (10⁻¹ S/cm), lowest conductance activation energy (50 meV near room temperature), and the most red-shifted polaron absorption (edge ~160 m, 8 meV).
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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".