Indenyl-Nickel Complexes Bearing a Pendant, Hemilabile Olefin Ligand: Preparation, Characterization, and Catalytic Activities
Bibliographic record
Abstract
The reaction of (PPh 3 ) 2 NiCl 2 with Li[Ind∧CH CH 2 ] gave the neutral complexes (η:η 0 -Ind∧CH CH 2 )Ni(PPh 3 )Cl (Ind = indenyl; ∧ = (CH 2 ) 2, 1a; Si(Me) 2 CH 2, 1b ), which were subjected to Cl - abstraction to give the corresponding cationic complexes [(η:η 2 -Ind∧CH CH 2 )Ni(PPh 3 )] + (∧ = (CH 2 ) 2, 2a; Si(Me) 2 CH 2, 2b ). The bis(phosphine) derivatives [(η:η 0 -Ind-CH 2 CH 2 CH CH 2 )Ni(PPh 3 ) 2 ] + ( 3a ) and [(η 3 -allyl)Ni(PPh 3 ) 2 ] + ( 4 ) formed gradually from room-temperature solutions of 2a and 2b, respectively, even in the absence of added PPh 3 . On the other hand, [(η:η 0 -Ind-SiMe 2 CH 2 CH CH 2 )Ni(PPh 3 ) 2 ] + ( 3b ) was detected only when PPh 3 was added to a CD 2 Cl 2 solution of 2b . The lability of the vinyl moiety in 2 allows these complexes to act as single-component precatalysts for the polymerization and hydrosilylation of styrene; the latter reaction requires little or no induction period with the hydrosilanes PhRSiH 2 (R= Ph, Me, H) and proceeds with up to 1000 catalytic turnovers. Compounds 1a, 1b, 2a, 3a, and 4 have been characterized by NMR and single-crystal X-ray diffraction studies, whereas 2b and 3b were identified by NMR spectroscopy. Structural information gleaned from both solid-state and solution data provide important information on the Ni−olefin bonding in 2a and 2b and indicate that the Ni−Ind interactions in these complexes are affected by the significant trans influence of the chelating olefin moiety.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.008 | 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".