Determination of thermodynamic p<i>K</i><sub>a</sub> values of benzimidazole and benzimidazole derivatives by capillary electrophoresis
Bibliographic record
Abstract
Thermodynamic pK(a) values for benzimidazole and several substituted benzimidazoles were determined by CE. Electrophoretic mobilities of benzimidazoles were determined by CE at different pH levels and ionic strengths. The dependence of electrophoretic mobilities on pH was used to obtain pK(a) values at different ionic strengths. Extrapolations to zero ionic strength were used to determine the thermodynamic pK(a) values. Using this method the thermodynamic pK(a) values of 15 benzimidazoles were determined and found to range from 4.48 to 7.38. Results from the CE measurements were compared with spectrophotometric measurements which were evaluated at wavelengths where the highest absorbance difference for varying pH was recorded. The two analytical techniques were in good agreement.
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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 | 0.001 | 0.003 |
| 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 | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".