Tuning Phosphine Oxide-Substituted <i>ortho</i>-Carboranes for Improved Biphasic Electrochemical UO<sub>2</sub><sup>2+</sup> Capture and Release
Bibliographic record
Abstract
We report the synthesis and characterization of a series of new, tunable 1,2-bis(diarylphosphine oxide)- ortho -carboranes, derivatives of our previously reported uranyl (UO 2 2+ ) capture agent 1,2-(Ph 2 PO) 2 -1,2-C 2 B 10 H 10 ( PO Cb ). The series features new cage-substituted variants of PO Cb, namely, 9-I- PO Cb ( PO CbI ), 9,12-I 2 - PO Cb ( PO CbI 2 ), 9,12-Me 2 - PO Cb ( PO CbMe 2 ), 9,12-Et 2 - PO Cb ( PO CbEt 2 ), and 4,5,7,8,9,10,11,12-Me 8 - PO Cb ( PO CbMe 8 ). Aryl-substituted variants include 1,2-((4-MeO-Ph) 2 PO) 2 -Cb ( (OMe)PO Cb ) and 1,2-((4-F-Ph) 2 PO) 2 -Cb ( (F)PO Cb ). The effects of electron-withdrawing (EWG) and electron-donating (EDG) groups on resulting carborane redox potentials were assessed using electrochemical means, and the resulting Lewis basicities were quantified using empirical and competition-based NMR experiments. In organic solution, carboranes substituted with EWGs exhibited weaker coordination to UO 2 2+, whereas those with EDGs exhibited stronger coordination. Similar to the previously reported unsubstituted PO Cb, the tunable new series of carboranes were electrochemically reduced and used for the biphasic capture of UO 2 2+ from an aqueous to an organic phase and back again (release) through electrochemical oxidation. Extraction and back-extraction efficiencies were determined by analyses of the aqueous phases by ICP-OES. While all reduced nido -carboranes efficiently extracted UO 2 2+ in high yields (78–88%)─with seemingly no correlation to the aforementioned measured Lewis basicities─we found the back-extraction of UO 2 2+ to be significantly improved from PO Cb and, surprisingly, more closely related to their hydrophobic rather than their Lewis basic properties.
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How this classification was reachedexpand
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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 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 teacher head, 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".