Photoswitchable azobenzene‐ and stilbene‐based chromophores bearing terminal nitro groups: Synthesis, thermal and photochemical properties
Bibliographic record
Abstract
Abstract This study examined the effects of aromatic cores and spacer lengths of chromophore structures on photoreactivity and mesomorphic properties of a series of azobenzene‐ and stilbene‐based chromophores bearing electron‐withdrawing (NO 2 ) terminal groups caused by esterification reactions. The chromophores were composed of liquid crystalline mesophases with six or 11 methylene segments as spacers and with azobenzene (NN) and stilbene (CC) aromatic cores. The target compounds were further characterised using nuclear magnetic resonance spectroscopy, differential scanning calorimetry, polarising optical microscopy, absorption and photoluminescence spectroscopies. All of the azobenzene and stilbene derivatives with six or 11 methylene segments showed enantiotropic mesophases and revealed chiral nematic phases (cholesteric, exhibiting oily streaks textures). S6 and S11 with stilbene cores showed broader phase transition temperature ranges than A6 and A11 with azobenzene cores because of the molecular interaction enhancement of the planar stilbene structure. We investigated the effects of these photochromic compounds' structures on E/Z photoisomerisation under UV irradiation. UV irradiation caused E/Z photoisomerisation at NN and CC segments of the chromophores, leading to reversible and irreversible isomerisation respectively. These synthesised chromophores with functionally photoisomerised groups might have potential application for photoinduced alignments in liquid crystal industries.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 teacher head, 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".