A New Arene-Bridged Diamidophosphine Ligand and Its Coordination Chemistry with Zirconium(IV)
Bibliographic record
Abstract
The arene-bridged dilithium diamidophosphine ligand, [(2,4,6-Me 3 C 6 H 2 )NLi-2-(5-MeC 6 H 3 )] 2 PPh, [NPN]*Li 2, was prepared from (2,4,6-Me 3 C 6 H 2 )(2-Br-4-MeC 6 H 3 )NH, n BuLi, and PhPCl 2 in Et 2 O and isolated as a dioxane adduct in ∼85% yield. The solid-state structure of [NPN]*Li 2 (THF) 2 as determined by X-ray diffraction shows both lithiums bridged by the amido nitrogens with one Li ion coordinated to the phosphine donor. The reaction of [NPN]*H 2 and Zr(NMe 2 ) 4 in toluene produced [NPN]*Zr(NMe 2 ) 2 in 90% isolated yield. Addition of excess Me 3 SiCl to [NPN]*Zr(NMe 2 ) 2 converts it to [NPN]*ZrCl 2 in high yield. The solid-state structure of [NPN]*ZrCl 2 as determined by X-ray diffraction shows the Zr center is a distorted trigonal bipyramid with the phosphine and the chloride apical. The ortho -Me's on the N-mesityl moiety are inequivalent in both the Li and Zr complexes of [NPN]* by NMR spectroscopy, while in [NPN]*H 2 MesN ortho -Me's appear as broad singlets. VT-NMR of [NPN]*H 2 indicated that Δ G rot ⧧ of MesC ipso −N is approximately 15.5 ± 0.3 kcal mol - 1 . The thermally labile and light-sensitive zirconium dimethyl complex [NPN]*ZrMe 2 was prepared from [NPN]*ZrCl 2 and MeMgCl in Et 2 O in 80% yield.
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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 | 0.001 |
| 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) | 0.008 | 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".