Polymerization of 1-hexene catalyzed by Cp*TiMe<sub>3</sub>-B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>; a mechanistic and structural study
Bibliographic record
Abstract
Solutions of the ZieglerNatta system Cp*TiMe 3 B(C 6 F 5 ) 3 in toluene catalyze the polymerization of 1-hexene to mixtures of atactic poly-1-hexenes and complex oligomeric materials, which were characterized by 1 H and 13 C{ 1 H} NMR spectroscopy and gel permeation chromatography (GPC). The polymer molecular weights and the relative proportions of polymers and oligomers vary with temperature, monomer:catalyst ratios, and degree of dilution and may generally be rationalized in terms of a conventional ZieglerNatta mechanism. The 13 C{ 1 H} NMR spectra of the polymers exhibit resonances suggesting significant degrees of 2,1-insertions during propagation, while experiments utilizing Cp*Ti( 13 CH 3 ) 3 verify that initiation in toluene involves predominantly via 1,2-insertion of the first monomer unit but that 2,1-insertions occur up to 1520% of the time in CH 2 Cl 2 . NMR experiments involving Cp*Ti( 13 CH 3 ) 3 demonstrate that both methyl groups in the presumed active species Cp*TiMe + 2 are incorporated into polymerKey words: titanium, polymers, polymerization, ZieglerNatta
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".