Synthesis, characterization, and single-molecule metamagnetism of new Co(ii) polynuclear complexes of pyridine-2-ylmethanol
Bibliographic record
Abstract
The reaction between pyridine-2-ylmethanol (HL), anhydrous CoCl(2) and NaH afforded polynuclear Co(II) complexes [Co(7)(L)(12)]Cl(2) (1), [Co(6)Na(L)(12)]Cl (2) and [Co(4)Cl(2)(L)(6)] (3), depending on the HL:CoCl(2) ratio set in the reaction. The core structures of the centrosymmetric complexes 1 and 2 are of the M@Co(6) type (M = Co or Na, respectively) with a coplanar arrangement of the metals whereas that of centrosymmetric 3 is of an incomplete dicubane type. The experimental conditions allowing interconversions between these polynuclear complexes have been determined, which provides a more rational control of their synthesis. Thus, 1 transforms to 3 when reacted with CoCl(2) in a 1 : 1 ratio, whereas the same reaction performed with a large excess of CoCl(2) gave the tetranuclear pseudo-cubane complex [Co(4)(L)(4)Cl(2)(MeOH)(4)] upon recrystallization. Conversely, 1 was isolated from the reaction of 3 with HL and NaH. The crystal structure of these compounds is reported, along with the magnetic behaviour of 1 and 3. The analysis of the magnetism using the effective spin-1/2 Hamiltonian approach revealed single-molecule metamagnetic behavior in 3.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".