Oxidative Ring-Opening of Aromatics: Decomposition\nof Biphenyl Carboxylic Acids and Zinc Biphenyl Carboxylates
Why this work is in the frame
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Bibliographic record
Abstract
Ring-opening\nconversion of multinuclear aromatics can be used to\nupgrade heavy aromatic oils to lighter products, and it is usually\nperformed reductively with H<sub>2</sub>. Oxidative ring-opening is\nan alternative strategy that involves three steps: (i) oxidation of\nmultinuclear aromatics to quinonoids, (ii) further oxidation and ring-opening\nto produce aromatic carboxylic acids, and (iii) decarboxylation of\naromatic carboxylic acids. In the last step, decomposition by ketonization\nis an undesirable side reaction that leads to a ring-closed product.\nSelectivity control during aromatic carboxylic acid decomposition\nwas investigated using biphenyl-2-carboxylic acid, biphenyl-2,2′-dicarboxylic\nacid, zinc(II) biphenyl-2-carboxylate, and zinc(II) biphenyl-2,2′-dicarboxylate.\nThe reaction networks of thermal decomposition of the aromatic carboxylic\nacids were determined. Decomposition of biphenyl-2-carboxylic acid\ntook place mainly by decarboxylation to produce biphenyl, dehydration\nand ring-closure to produce fluorenone, and the formation of diphenic\nanhydride as intermediate product leading to fluorenone. Decomposition\nof biphenyl-2,2′-dicarboxylic acid proceeded through decarboxylation\nto biphenyl-2-carboxylic acid as intermediate, as well as two seemingly\nrelated pathways, leading to the formation of a hydroxy-fluorenone\nand a cyclic trione. Over the temperature range from 340 °C to\n400 °C, thermal decomposition invariably resulted in a higher\nketonization than decarboxylation selectivity. Decomposition of the\nanalogous zinc carboxylates demonstrated that ketonization could be\nsuppressed and the most abundant products were biphenyl > fluorenone\n> fluorene. It was possible to achieve a biphenyl (decarboxylation)\nto fluorenone (ketonization) selectivity ratio of 17:1 during batch\nreactor decomposition of zinc(II) biphenyl-2,2′-dicarboxylate\nat 380 °C. Reaction stoichiometry indicated that water should\naffect selectivity, which is consistent with observations in the literature,\nbut this aspect was not investigated further.
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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 | 0.001 |
| 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.035 | 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 it