A Study of 13C Chemical Shifts for a Series of 2-(4-methoxyphenyl)-substituted-3-phenyl-1,3-thiazolidin-4-ones
Bibliographic record
Abstract
The 13C substituent chemical shifts C-2, C-4 and C-5 (with a particular focus at C-2) for disubstituted 2,3-diphenylthiazolidin-4-ones with one substituent in each phenyl ring are systematically being investigated. The substituents in question are p-NO2, m-NO2, p-F, m-F, p-Cl, m-Cl, p-Br, m-Br, H, p-CH3, m-CH3, p-OCH3 and m-OCH3. This combination of substituents leads to a 13 x 13 matrix array of compounds with the fixed substituents in the 2-phenyl ring constituting the columns and the fixed substituents in the 3-phenyl rings constituting the rows. Including this present study, 81 of the total 169 compounds in the matrix have been analyzed. A single para-methoxy group interacting with another fixed substituent, as measured by 13C substituent chemical shift values at C-2 in either the C-2 phenyl or N-3 phenyl rings, shows little deviation. This changes however when the moiety is either an alkyl group at N-3 or when a para-methoxy group is the fixed substituent on the N-3 phenyl ring. This present study shows that a para-methoxy group on a C-2 phenyl ring shows a similar deviation in the efficacy in the transmission of electronic effects witnessed in this set of matrix compounds and mimics the issues seen with a previously studied para-methoxy substituted system with the para-methoxy group on the N-3 phenyl ring. Reasons for these aberrations are discussed.
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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 | 0.001 |
| 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".