Structure and magnetic behaviour of mono- and bimetallic chromium(iii) complexes of amine-bis(phenolate) ligands
Bibliographic record
Abstract
Two lithium amine-bis(phenolate) and four chromium(III) amine-bis(phenolate) complexes have been prepared. The diprotonated tripodal tetradentate ligand precursors 2-tetrahydrofurfuryl-N,N-bis(2-methylene-4-methyl-6-tert-butylphenol), H(2)[O(2)NO](BuMe); 2-tetrahydrofurfuryl-N,N-bis(2-methylene-4,6-tert-butylphenol), H(2)[O(2)NO](BuBu); 2-pyridylamino-N,N-bis(2-methylene-4,6-methylphenol), H(2)[O(2)NN'](MeMe); and 2-pyridylamino-N,N-bis(2-methylene-4,6-tert-butylphenol), H(2)[O(2)NN'](BuBu); can be lithiated using n-butyllithium. Isolation of the Li(2)[O(2)NO](RR') compounds generates dimeric {Li(2)[O(2)NO](RR')}(2) (R = t-Bu, R' = Me in 1 and R = R' = t-Bu in 2) in the solid state as shown by single-crystal X-ray diffraction. The lithiated ligands were used to prepare a series of Cr(III) complexes. Monometallic complexes are obtained when prepared and purified under strictly anhydrous conditions, giving CrCl(THF)[O(2)NO](RR') (R = t-Bu, R' = Me in 3 and R = R' = t-Bu in 4). However, bimetallic Cr complexes are obtained upon recrystallization in air, where adventitious water reacts with the complex resulting in protonation of one of the phenolate groups of the ligand and generating hydroxide, which bridges two Cr(III) centres. Solid-state single-crystal X-ray diffraction studies of {CrCl[O(2)NN'](MeMe)}(mu-HO){CrCl[HO(2)NN'](MeMe)}, 5, and {CrCl[O(2)NN'](BuBu)}(mu-HO){CrCl[HO(2)NN'](BuBu)}, 6, were performed. The paramagnetic Cr(III) complexes were also characterized by UV-vis spectroscopy, mass spectrometry and magnetic measurements.
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) | 0.006 | 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".