Thorium(<scp>iv</scp>) alkyl and allyl complexes of a rigid NON-donor pincer ligand with flanking 1-adamantyl substituents
Bibliographic record
Abstract
Palladium-catalyzed coupling of 1-adamantylamine (2 equiv.) with 4,5-dibromo-2,7-di-tert-butyl-9,9-dimethylxanthene afforded the proligand 4,5-bis(1-adamantylamino)-2,7-di-tert-butyl-9,9-dimethylxanthene, H2[XAd] (1), which upon deprotonation with excess KH or KCH2Ph in THF or dme generated [{K(THF)3}2(XAd)] (2a) and [K2(XAd)(dme)] (2b). Subsequent reaction of in situ generated 2a or 2b with [ThCl4(dme)2] yielded [(XAd)ThCl4K2]·x(dme) (3; x = 0.5-2), which reacted with 2 equiv. of LiCH2SiMe3 or K[allylTMS] to afford the bis(hydrocarbyl) complexes [(XAd)Th(CH2SiMe3)2(THF)] (4) and [(XAd)Th(η3-allylTMS)2] {5; allylTMS = 1-(SiMe3)C3H4}. Dialkyl complex 4 was stable at 80 °C for at least 2.5 hours, but decomposed over 4.5 hours at 110 °C. Diallyl complex 5 was stable for hours at 85 °C, and suffered less than 5% decomposition after 10 minutes at 155 °C. At room temperature, averaging of the syn and anti protons of the allyl CH2 groups of 5 occurred on the NMR timescale, as a consequence of rapid π-σ-π hapticity changes. Additionally, low temperature 1H and 13C NMR spectroscopy indicates that 5 exists as a rapidly exchanging mixture of two isomers with C1 and C2 symmetry. Compounds 2a, 4 and 5 were crystallographically characterized.
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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) | 0.000 | 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".