Extraction of Several Divalent Metal Picrates by 18-Crown-6 Ether Derivatives into Benzene: A Refinement of Methods for Analyzing Extraction Equilibria
Bibliographic record
Abstract
Three kinds of extraction constants, Kex, Kex±, and Kex+, were evaluated from the improved model that the following three component-equilibria were added to a previously-proposed model for an overall extraction: M2+ + A-===MA+, MLA+Bz + A-Bz===MLA2,Bz, and A-===A-Bz. Here, Kex, Kex±, and Kex+ were defined as [MLA2]Bz/([M2+][L]Bz[A-]2), [MLA+]Bz[A-]Bz/([M2+][L]Bz[A-]2), and [MLA+]Bz/([M2+][L]Bz[A-]), respectively; the subscript “Bz” denotes benzene as an organic phase. The symbols correspond to M2+ = Ca2+ and Pb2+, L = 18-crown-6 ether (18C6) and dibenzo-18C6 (DB18C6), and A- = picrate ion. The ion-pair formation constant for M2+ + A-===MA+ at M2+ = Pb2+ in an aqueous phase was also determined at 298 K and ionic strength of zero by an extraction of HA into 1,2-dichloroethane and Bz with the presence of Pb2+ in the aqueous phase. The Kex values re-evaluated from the present model were in agreement with those determined by the previous extraction model. Individual distribution constants of A- into Bz were almost constant irrespective of kinds of M2+ and L employed. Furthermore, the composition-determination method of the ion pairs, MLA2, extracted into Bz was re-examined. Similar analyses were performed in the SrA2-, BaA2-18C6, and SrA2-DB18C6 systems without considering the formation of MA+ in the aqueous phases.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 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 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 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".