Arene Complexes of β‐Diketiminato Supported Organoscandium Cations: Mechanism of Arene Exchange and Alkyne Insertion in Solvent Separated Ion Pairs
Bibliographic record
Abstract
A family of isolable solvent separated organoscandium methyl cations stabilized by beta-diketiminato ligands (Ar)NC(CH3)CHC(CH3)N(Ar) (Ar=2,6-iPr-C6H3, LMe) has been prepared by reaction of LMeScR2 with [CPh3][B(C6F5)4] in the presence of an arene solvent. Arenes such as bromobenzene, benzene, toluene, para-xylene and mesitylene bind the scandium center in an eta6-bonding mode, yielding cations 1 a-e. Their solution and solid-state structures have been explored using multinuclear NMR spectroscopy and X-ray crystallography. Mechanistic studies on arene exchange reactions and the insertion of diphenylacetylene indicate that these processes occur via arene intermediates of lower hapticity, followed by binding of the incoming reagent. Which of the two steps is rate limiting depends on the arene being displaced and/or the nature of the incoming substrate. The experiments present a unified view of these mechanisms, which have relevance to propagation processes in olefin polymerizations mediated by such cations.
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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 | 0.000 |
| 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) | 0.009 | 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".