Serendipitous Isolation of the First Example of a Mixed-Valence Samarium Tripyrrole Complex
Bibliographic record
Abstract
The transamination reaction of Sm{N(SiMe 3 ) 2 } 2 (THF) 2 with two dipyrrole ligands of formula RR‘C(α-C 4 H 3 NH) 2 (R = R‘ = Et; R = Me, R‘ = Ph) has been examined. The reactions in THF and under N 2 gave two similar tetranuclear dinitrogen complexes, {[Et 2 C(α-C 4 H 3 N) 2 Sm} 4 (THF) 2 ](μ-N 2 )·2THF and [{[(C 6 H 5 )(CH 3 )C(α-C 4 H 3 N) 2 ]Sm} 4 (DME) 2 ](μ-N 2 ), where the dinitrogen unit has undergone a four-electron reduction via cooperative attack of four divalent samarium atoms and remained coordinated both side-on and end-on between the four coplanar metal centers. The same reaction carried out with diethyldipyrrolylmethane under an argon atmosphere afforded the divalent samarium macrocyclic cluster {[Et 2 C(α-C 4 H 3 N) 2 ]Sm} 8 (THF) 4 ·4THF. In the case of the reaction with the methylphenyldipyrrolylmethane ligand under N 2, the unprecedented hexanuclear mixed-valence Sm II /Sm III cluster [([(C 6 H 5 )(CH 3 )C(α-C 4 H 3 N) 2 ][(C 6 H 5 )(CH 3 )C(α-C 4 H 3 N)(β-C 4 H 3 N)]{[(C 6 H 5 )(CH 3 )C] 2 (α-C 4 H 3 N) 2 (α,α‘-C 4 H 2 N)}Sm 3 )(THF) 3 ] 2, containing tripyrrolide, “N-confused”, and regular dipyrrolide ligands was serendipitously formed by reaction with the impurities contained in the nonpurified ligand.
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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) | 0.002 | 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".