Accelerated Ligand Metalation in a β-Diketiminato Scandium Dimethyl Complex Activated with Bis(pentafluorophenyl)borane
Bibliographic record
Abstract
Equimolar reactions of LScMe 2 (L = (Ar)NC( t Bu)CHC( t Bu)N(Ar); Ar = 2,6- i Pr 2 -C 6 H 3 ) and HB(C 6 F 5 ) 2 proceed through an isolable ion pair 2 to a metalated scandium borate 3 with loss of methane. Multinuclear NMR experiments confirm the proposed structure, which was also verified by synthesis via alternative routes and derivatization. Deuterium labeling studies offer insight into the mechanism of methane loss, which occurs through C−H activation of an abstracted methide rather than the direct intramolecular metalation commonly observed for β-diketiminato scandium alkyl complexes. A large primary kinetic isotope effect of k H / k D = 8.7(6) was observed for the decomposition of 2, which corroborates the proposed mechanism while also implicating a highly reactive four-membered scandocycle intermediate, LSc((H)CH 2 B(C 6 F 5 ) 2 ). Reaction of 2 equiv of HB(C 6 F 5 ) 2 with LScR 2 yields μ 2 -hydridoborate complexes [LScCH 3 ][(μ-H) 2 B(C 6 F 5 ) 2 ] ( 5 ), while 4 equiv of borane react to afford the bis-μ 2 -hydridoborate complex [LSc][(μ-H) 2 B(C 6 F 5 ) 2 ] 2, 6 .
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.003 |
| 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) | 0.024 | 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".