Ionization of Cp<sub>2</sub>ZrMe<sub>2</sub> and Lewis Bases by Methylaluminoxane: Computational Insights
Bibliographic record
Abstract
Abstract The interactions of the Lewis bases CO, octamethyltrisiloxane (OMTS) and 2,2’‐bipyridine (bipy) with a sheet model for the principal activator (MeAlO) 16 (Me 3 Al) 6 ( 16,6 ) in hydrolytic methylaluminoxane (MAO) were investigated by DFT. These studies reveal that OMTS and bipy form adducts with Me 3 Al prior to methide abstraction by 16,6 to form the ion‐pairs [Me 2 Al(κ 2 ‐L)][ 16,6 ] ( 5 : L=OMTS, 6 : L=bipy, [ 16,6 ] − =[(MeAlO) 16 (Me 3 Al) 6 Me] − ) while CO simply binds to a reactive edge site without ionization. The binding and activation of Cp 2 ZrMe 2 with 16,6 to form both neutral adducts 1 Cp 2 ZrMe 2 ⋅ 16,6 and contact ion‐pairs 4 and 7 , both with formula [Cp 2 ZrMe][μ‐Me(MeAlO) 16 (Me 3 Al) 6 ], featuring terminal and chelated MAO‐anions, respectively was studied by DFT. The displacement of the anion with either excess Cp 2 ZrMe 2 or Me 3 Al was also studied, forming outer‐sphere ion‐pairs [(Cp 2 ZrMe) 2 μ‐Me][ 16,6 ] ( 2 ) and [Cp 2 Zr(μ‐Me) 2 AlMe 2 ][ 16,6 ] ( 3 ). The theoretical NMR spectra of these species were compared to experimental spectra of MAO and Cp 2 ZrMe 2 and found to be in good agreement with the reported data and assignments. These studies confirm that 16,6 is a very suitable model for the activators present in MAO but highlight the difficulty in accurately calculating thermodynamic quantities for molecules in this size regime.
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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 | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".