Titanium Complexes of Sterically Demanding Cage-Phosphinimide Ligands
Bibliographic record
Abstract
The known ligand PPh(C 6 H 4 O 3 Me 4 ) ( 1 ) and its analogue PCy(C 6 H 4 O 3 Me 4 ) ( 2 ) have been prepared. In the latter synthesis the diphosphine species (PCy) 2 (C 6 H 2 O 3 Me 4 ) ( 3 ) was also isolated as a minor product. Reaction of the cage phosphines 1 and 2 with Me 3 SiN 3 effected oxidation to the corresponding (trimethylsilyl)phosphinimines Me 3 SiNPR(C 6 H 4 O 3 Me 4 ) (R = Ph ( 4 ), Cy ( 5 )). Subsequent reactions afforded the titanium complexes CpTiCl 2 (NPR(C 6 H 4 O 3 Me 4 )) (R = Ph ( 6 ), Cy ( 7 )) and CpTiMe 2 (NPR(C 6 H 4 O 3 Me 4 )) (R = Ph ( 8 ), Cy ( 9 )). Preliminary screening for catalytic activity in ethylene polymerization employing either methylalumoxane (MAO) or [Ph 3 C][B(C 6 F 5 ) 4 ] as the activator showed minimal catalytic activity. These observations were probed via reactions of these complexes with AlMe 3, MAO, or [Ph 3 C][B(C 6 F 5 ) 4 ]. Reaction of 8 with AlMe 3 gave several products, one of which was fully characterized as the cage-rupture product CpTiMe 2 (NPCy(C 6 H 4 O 3 Me 5 )(μ-AlMe 2 )(AlMe 3 )) ( 10 ). A similar product is inferred by the spectroscopic monitoring of the reaction of 8 with MAO. In contrast, reaction of 2 with AlMe 3 resulted only in the formation of the adduct Me 3 AlPCy(C 6 H 4 O 3 Me 4 ) ( 11 ). Structural data are reported for 2, 3, 8, 10, and 11 .
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.262 | 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".