Harnessing Direct (Hetero)Arylation in Pursuit of a Saddle-Shaped Perylene Diimide Tetramer
Bibliographic record
Abstract
This contribution explores the direct (hetero)arylation (DHA) cross-coupling of a saddle-like, π-conjugated cyclooctatetrathiophene ( Th 4 ) core with the N-annulated perylene diimide (PDI) chromophore. Replacing the bulky pivalic acid with acetic acid enabled a facile cross-coupling, selectively forming a PDI tetramer ( Th 4 PDI 4 ) in a 70% overall yield. The optoelectronic properties of Th 4 PDI 4 were characterized and density functional theory (DFT) was used to calculate the optimized molecular geometry and molecular orbitals (MOs). Energy levels of MOs determined by cyclic voltammetry corresponded well with those calculated using DFT. The molecular geometry calculated by DFT showed Th 4 PDI 4 adopts two separate PDI–PDI conformations (propeller and double-decker). Organic photovoltaic (OPV) devices were fabricated using a blend of PTB7-Th/ Th 4 PDI 4, where an initial power conversion efficiency (PCE) of 1.89% was improved by testing a series of solvent additives and thermal annealing techniques. Through use of 3% (v/v) 1-chloronaphthalene additive, a combination of higher short circuit current ( J sc = 10.2 mA/cm 2 ) and fill factor (FF = 42%) led to an overall increase in PCE to 4.26%.
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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 | 0.001 |
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".