Synthesis and structure of mono-, bi- and trimetallic amine-bis(phenolate) cobalt(ii) complexes
Bibliographic record
Abstract
A series of cobalt(ii) amine-bis(phenolate) complexes has been prepared and characterized. The protonated tripodal tetradentate ligand precursors; dimethylaminoethylamino-N,N-bis(2-methylene-4-tert-butyl-6-methylphenol), H(2)[O(2)NN'](BuMeNMe2), dimethylaminoethylamino-N,N-bis(2-methylene-4,6-di-tert-butylphenol), H(2)[O(2)NN'](BuBuNMe2), diethylaminoethylamino-N,N-bis(2-methylene-4,6-di-tert-amylphenol), H(2)[O(2)NN'](AmAmNEt2) and 2-pyridylamino-N,N-bis(2-methylene-4,6-di-tert-amylphenol), H(2)[O(2)NN'](AmAmPy); were reacted with cobaltous acetate tetrahydrate under varying conditions to afford a range of monometallic, bimetallic and trimetallic species. An unusual four coordinate complex Co[O(2)NN'](AmAmNEt2) containing Co(II) in a trigonal monopyramidal environment was structurally characterized, whereas using a less sterically demanding ligand a series of five coordinate complexes Co[O(2)NN'](BuBuNMe2)(L) (L = H(2)O, CH(3)OH, (CH(3))(2)C[double bond, length as m-dash]O, propylene oxide) containing Co(II) in a trigonal bipyramidal environment was prepared. A new angular structural parameter related to tau is defined, where tau' may be used to compare complexes with trigonal monopyramidal structures. In contrast, ligands containing a pendant pyridyl donor afford dimeric species including {Co(mu-CH(3)OH)[O(2)NN'](AmAmPy)}(2). In the absence of base and in the presence of excess cobaltous acetate, trimetallic complexes were isolated containing a central Co(II) in an octahedral environment coordinated to four CH(3)OH and two bridging acetate ligands between two Co[O(2)NN'] fragments with Co(II) in a trigonal bipyramidal setting. The paramagnetic Co(II) complexes reported were also characterized by UV-vis spectroscopy, mass spectrometry, cyclic voltammetry and magnetic measurements.
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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) | 0.017 | 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".