Experimental and Theoretical Study of the High-Temperature UV–Visible Spectra of Aqueous Hydroquinone and 1,4-Benzoquinone
Bibliographic record
Abstract
UV-visible spectroscopic studies of aqueous hydroquinone (HQ) and 1,4-benzoquinone (BQ) have been carried out along with classical molecular dynamics (MD) and quantum calculations. The experimental results confirmed that HQ is stable in hot compressed water up to at least 523 K at 70 bar, but BQ decomposes at temperatures lower than 373 K, leading to the formation of HQ and other nonabsorbing products. Even though benzoquinone is not stable, our study significantly extended the temperature range of other spectroscopic studies, and the spectra of HQ up to 523 K can still be useful for other studies, particularly those related to organic species in deep ocean hydrothermal vents. Classical MD simulations at high temperatures show, as expected, a weakening of the solute-solvent H-bonding interactions. The dependence of the maximum absorption of BQ on temperature was also analyzed, although a significant degree of decomposition was observed in the time frame of our experiments. The shift of the maximum absorption peak of BQ with temperature was consistent with time-dependent density functional theory calculations.
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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 | 0.001 |
| 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".