Activation of chlorobenzene with Ni(0) <i>N</i>,<i>N</i>-chelates A remarkably profound effect of a minuscule change in ligand structure
Bibliographic record
Abstract
Activation of the CCl bond of chlorbenzene with [(COD) 2 Ni] and a bidentate N,N-ligand such as N,N,N′,N′-tetramethylethylenediamine (tmeda) and 2,2′-bipyridyl (bipy) has been reported to produce σ-phenyl complexes [(tmeda)Ni(Ph)Cl] (1) and [(bipy)Ni(Ph)Cl], respectively. However, in sharp contrast, we found that similar reactions involving almost the identical ligands N,N,N′,N′-tetraethylethylenediamine (teeda) and 6,6′-dimethyl-2,2′-bipyridyl (6,6′-Me 2 bipy) resulted in homocoupling and the formation of non-organometallic dichlorocomplexes [(teeda)NiCl 2 ] and [(6,6′-Me 2 bipy)NiCl 2 ]. The latter two compounds and 1 were characterized by single-crystal X-ray diffraction data. The remarkable change in the reaction outcome points to its extremely high sensitivity to minor alterations in the structure of the stabilizing N,N-ligand. In contrast, analogous reactions of [Pd(dba) 2 ] with PhI in the presence of teeda or 1,2-dipiperidinoethane (dpe) produced the expected σ-phenyl complexes [(teeda)Pd(Ph)I] and [(dpe)Pd(Ph)I], much like the previously reported reaction with tmeda.Key words: C-Cl activation, zerovalent nickel complexes, N,N-ligands, oxidative addition, homocoupling, X-ray analysis.
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) | 0.000 | 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) | 0.000 | 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".