Photophysical Investigations of\nThiophene Azomethine Derivatives
Bibliographic record
Abstract
A series of sterically hindered thiophene-aniline azomethine dyads were prepared.The decay pathways that deactivate the singlet excited state were studied using UV-vis fluorescence and phosphorescence, laser flash photolysis and quantum calculations.Stern-Volmer relationships, derived from singlet and triplet state quenching experiments, showed that azomethines efficiently deactivate the singlet and triplet excited states of fluorophores with bimolecular kinetics.AM1 Semi-empirical quantum calculations examining the effect of bulky substituents on the bond rotational barriers demonstrate that bulky tert-butyl groups attached to the aniline moiety have less influence on the Naryl bond rotation barrier than alkyl substitutions do on the thiophene-CH bond rotation barrier.Rehm-Weller calculations based on electrochemical potentials demonstrate that azomethines self-quench their excited states via fast and efficient intramolecular photoinduced electron transfer leading to complete fluorescence suppression.Metal complexes containing an azomethine ligand were also prepared.The ligand contains a hydroxyquinoline moiety linked with a thiophene ring.Photophysical investigations of the resulting metal complexes demonstrated significant bathochromic shifts in the absorbance and fluorescence spectra.Metal-ion sensing devices for water solutions were prepared by spin casting the ligand onto glass slides.The metal-ion sensor detected copper in water solutions through a bathochromic shift in the absorbance maximum.
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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) | 0.003 | 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".