On the photoreactivity of vitamin K compounds
Bibliographic record
Abstract
Abstract Rate constants for conversion of vitamin K1‐and K2‐derived 1,3‐quinone methides into 1,2‐quinone methides have been measured in CH3CN solutions in the presence of Brönsted acids and bases. Second‐order rate constants approach the diffusion‐controlled limit and are essentially independent of the (acid or base) strength of the catalyst. On the other hand, rate constants for triplet quenching of 2‐methyl‐3‐undecyl‐1,4‐naphthoquinone, used as model compound, are presented and compared with data for 1,4‐naphthoquinone and 2‐methyl‐1,4‐naphthoquinone. A significant decrease in reactivity is observed as the number of alkyl substituents in the quinoid moiety increases, which is attributed to the concomitant increase in triplet π,π* character. Correlation of rate constants for physical quenching, by aromatic hydrocarbons and dimethylsulfoxide, with the electron affinity of the (ground state) quinone and ionization potential of the quenchers suggests quenching by charge‐transfer interactions. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 839–844, 2008
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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 | 0.001 |
| 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 | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".