Phosphinimide complexes with pendant hemilabile donors: synthesis, structure and ethylene polymerization activity
Bibliographic record
Abstract
The phosphines tBu(2)P(CH(2))(3)ECH(2)Ph (E = O (1), S (2)) converted to the corresponding phosphinimines (Me(3)SiN)PtBu(2)(CH(2))(3)ECH(2)Ph, E = O (3), S (4)) which were used to prepared the titanium complexes Cp'TiCl(2)NPtBu(2)(CH(2))(3)ECH(2)Ph, (E = O, Cp' = Cp (5), Cp* (6); E = S, Cp' = Cp (7), Cp* (8)). These species were subsequently methylated to the corresponding dimethyl-derivatives (9)-(12). Activation of (9)-(12) with both B(C(6)F(5))(3) and [Ph(3)C][B(C(6)F(5))(4)] was studied. For example, the [CpTiMe(NPtBu(2)(CH(2))(3)OCH(2)Ph)][MeB(C(6)F(5))(3)] (13) reacted with THF to give [CpTiMe(THF)(NPtBu(2)(CH(2))(3)OCH(2)Ph)][MeB(C(6)F(5))(3)] (14). Similar reactions gave the stable ion pairs [Cp'TiMe(NPtBu(2)(CH(2))(3)XCH(2)Ph)][MeB(C(6)F(5))(3)] (X = O, Cp' = Cp*, (15); X = S Cp' = Cp, (16), Cp*(17)) and [Cp'TiMe(NPtBu(2)(CH(2))(3)XCH(2)Ph)][B(C(6)F(5))(4)] (X = O, Cp' = Cp, (18); Cp*(19); X = S, Cp' = Cp, (20), Cp* (21)). The dihalide complexes (5)-(8), activated with MAO, proved to be ethylene polymerization catalysts of moderate activities. The dialkyl titanium complexes (9)-(12) activated with B(C(6)F(5))(3) or [Ph(3)C][B(C(6)F(5))(4)], gave catalysts that exhibited substantially higher activity and high molecular weight polyethylene. Polymerization at 60 degrees C rather than 30 degrees C significantly increased activity as well. The impact of the hemilabile donor with respect to catalyst activity is discussed. Crystallographic studies of (5) and (6) are reported.
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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) | 0.014 | 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".