Synthesis and Characterization of the New Alkyl Borates [RB(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>]<sup>-</sup> (R = CH<sub>2</sub>Me, CHMe<sub>2</sub>, CH<sub>2</sub>CMe<sub>3</sub>): Utilization of [Me<sub>3</sub>CCH<sub>2</sub>B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>]<sup>-</sup> as a Weakly Coordinating Counteranion during Zirconocene-Induced Catalysis of Propylene Polymerization
Bibliographic record
Abstract
Reactions of alkyllithium compounds RLi (R = Me, Et, i -Pr, Np) with B(C 6 F 5 ) 3 result in the formation of the alkylborate salts Li[RB(C 6 F 5 ) 3 ]. Metathesis reactions of these with Ph 3 CCl and chloride salts of (Ph 3 P) 2 N +, PMePh 3 +, and HNMe 2 Ph + proceed with varying degrees of success, as shown by NMR spectroscopy and electrospray mass spectrometry, and the compounds [PPN][EtB(C 6 F 5 ) 3 ], [PMePh 3 ][NpB(C 6 F 5 ) 3 ], and [HNMe 2 Ph][NpB(C 6 F 5 ) 3 ] have been characterized crystallographically. All three anions assume the expected pseudotetrahedral structures with normal B−aryl bond lengths and R−B−aryl and aryl−B−aryl bond angles. The compound [HNMe 2 Ph][NpB(C 6 F 5 ) 3 ] reacts with Cp 2 ZrMe 2, (Indenyl) 2 ZrMe 2, and SBIZrMe 2 to give propylene polymerization catalysts that are significantly more active and give higher molecular weight polypropylene than do the catalysts obtained using B(C 6 F 5 ) 3 . Thus the [NpB(C 6 F 5 ) 3 ] - anion is for steric reasons more weakly coordinating than is [MeB(C 6 F 5 ) 3 ] - .
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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 | 0.009 | 0.007 |
| Meta-epidemiology (narrow) | 0.015 | 0.017 |
| Meta-epidemiology (broad) | 0.017 | 0.009 |
| Bibliometrics | 0.010 | 0.025 |
| Science and technology studies | 0.007 | 0.005 |
| Scholarly communication | 0.005 | 0.012 |
| Open science | 0.010 | 0.007 |
| Research integrity | 0.009 | 0.009 |
| Insufficient payload (model declined to judge) | 0.000 | 0.002 |
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; both teacher heads agree on what is shown here.
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".