(Py)<sub>2</sub>Co(CH<sub>2</sub>SiMe<sub>3</sub>)<sub>2</sub> As an Easily Accessible Source of “CoR<sub>2</sub>”
Bibliographic record
Abstract
(Py) 2 CoR 2 (R = CH 2 SiMe 3 ) is easily prepared from (Py) 4 CoCl 2 and RLi. It is fairly stable at room temperature and serves as a convenient source of CoR 2 for transfer to other ligands. Unfortunately, (Py) 2 CoR 2 was obtained only as an oil, but the structure of the related complex (Py) 2 CoR′ 2 (R′ = CH 2 CMe 2 Ph) could be confirmed by a single-crystal X-ray diffraction study. Transfer of the CoR 2 fragment from (Py) 2 CoR 2 or (TMEDA)CoR 2 to diiminepyridine-type ligands ( 1 − 6 ) was studied as a function of ligand steric and electronic properties. Reaction with N -2,6-dimethylphenyl ( 1 ) and N -2,4,6-trimethylphenyl ( 2 ) ligands produced diamagnetic mono alkyl complexes; the structure of ( 1 )CoR was confirmed by X-ray diffraction. With the less shielding N -phenyl ( 3 ) and N -benzyl ( 4 ) ligands, 1 H NMR indicated formation of diamagnetic Co I alkyl species, but they were not stable enough to allow isolation. Fluorinated ligand 5 appears to be less reactive and−despite its supposedly stronger π-acceptor character−also does not lead to formation of a stable Co I alkyl complex. With PyBOX ligand 6, high-spin di alkyl complex ( 6 )CoR 2 was observed by 1 H NMR. Based on these observations and DFT calculations, a mechanism is proposed for formation of diiminepyridine Co I alkyls that involves formation of a high-spin κ 2 complex, spin flip to give a low-spin κ 3 complex, and irreversible loss of an alkyl radical.
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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 | 0.003 | 0.002 |
| Meta-epidemiology (narrow) | 0.005 | 0.005 |
| Meta-epidemiology (broad) | 0.006 | 0.003 |
| Bibliometrics | 0.003 | 0.007 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.007 | 0.003 |
| Research integrity | 0.003 | 0.005 |
| Insufficient payload (model declined to judge) | 0.003 | 0.004 |
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; both teacher heads agree on what is shown here.
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".