A Supramolecular [π-radical]<sub>2</sub> Unit Acts as a Ligand: Coordination of La and Ce by a Pancake-Bonded Pair
Bibliographic record
Abstract
Preorganization of a supramolecular unit composed of two π-radicals generates a ligand with an unusual square-shaped tetradentate binding site, ideal for coordination to early lanthanide ions. The supramolecular unit is assembled via a pairwise interaction between two neutral radicals, creating a pancake-bonded diamagnetic [π-radical]2 dimer. Synthesis and characterization of the new π-radical bitaDTDA (4-(3′-benzisothiazolyl)-1,2,3,5-dithiadiazolyl) is reported. Unlike most DTDA-based ligands in which a supramolecular [π-radical]2 pair dissociates to generate a bidentate, paramagnetic ligand, the pancake-bonded [bitaDTDA]2 unit apparently remains intact upon coordination to early lanthanide ions capable of supporting a 10-coordinate ligand sphere. The Ln(hfac)3[bitaDTDA]2 complexes (Ln = La, Ce; hfac = 1,1,1,5,5,5-hexafluoroacetylacetonato) are readily prepared by manual mechanochemical methods, indicating a low energy barrier to coordination. Only minor conformational changes are evident in the supramolecular [bitaDTDA]2 ligand upon coordination. A structural comparison of the free [bitaDTDA]2 ligand and Ln(hfac)3[bitaDTDA]2 coordination complexes indicates favorable preorganization of the ligand.
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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 | 0.001 | 0.001 |
| 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 | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".