Highly Diverse Bonding between Two U<sup>3+</sup> Ions When Ligated by a Flexible Polypyrrolic Macrocycle
Bibliographic record
Abstract
A Schiff-base polypyrrolic ligand (H 4 L) can accommodate two U 3+ ions and form a Pacman-like complex [U 2 (L)] 2+ according to relativistic density functional theory. Sixteen species, featuring four structural models in four electronic states, are energetically stable. Ligand flexibility, lack of axial restriction, and suitable U–N interactions allow the two U 3+ ions to stretch freely over a wide range, in contrast to U 2 @C n ( n = 60, 74, 80) studied previously. Diverse U 3+ –U 3+ interactions are found. The quintet state of the Out–In model, which is calculated to be the global ground state both including and excluding the spin–orbit coupling energy, likely shows a weak single U 2 bond. In both vertical and tilt In–In species, a triple bond is found. It is composed of two two-electron–two-center bonds and two one-electron–two-center bonds; moreover, the tilt conformer is almost isoenergetic with Out–In. The Out–Out species shows no U···U bonding. Comparison with explicitly THF-solvated diuranium complexes is also addressed.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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 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".