Possible Thermal Decomposition Routes in [MeB(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>]<sup>-</sup>[L<sub>2</sub>TiMe<sup>+</sup>] as Deactivation Pathways in Olefin Polymerization Catalysis: A Combined Density Functional Theory and Molecular Mechanics Investigation
Bibliographic record
Abstract
Combined quantum mechanical (QM) and molecular mechanical (MM) models (QM/MM) have been used to explore possible decomposition routes for ion pair systems used as catalysts in olefin polymerization. The catalyst systems include [MeB(C 6 F 5 ) 3 ] - [(NPR 3 ) 2 TiMe + ], [MeB(C 6 F 5 ) 3 ] - [(Cp)(NCR 2 )TiMe + ], and [MeB(C 6 F 5 ) 3 ] - [(Cp)(SiMe 2 NR)TiMe + ]. The possible thermal decomposition routes for the above catalyst systems include fluorine transfer from [MeB(C 6 F 5 ) 3 ] - to the metal center, aryl transfer (C 6 F 5 ) to the growing chain, transfer of B(C 6 F 5 ) 3 from [MeB(C 6 F 5 ) 3 ] - to the ancillary ligand, exchange of methyl on butyl from the ancillary ligand with aryl in [MeB(C 6 F 5 ) 3 ] -, transfer of hydrogen from the Cp* ring to the growing chain, and transfer of hydrogen from the methyl group on tertiary butyl to the growing chain. The activation barriers fall in the range 15.5−68.7 kcal/mol. The transfer of fluorine from the counterion to the metal center is the most facile deactivation pathway.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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) | 0.002 | 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 source (direct Gemma or distilled Codex), 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".