A Synthetic, Structural, Spectroscopic, and Computational Study of Alkali Metal–Thioether, −Selenoether, and −Telluroether Interactions
Bibliographic record
Abstract
The rigid thioether- and selenoether-containing pro-ligands, 4,5-bis(phenylsulfido)-2,7,9,9-tetramethylacridan (H[AS 2 Ph2 ] ( 1 )) and 4,5-bis(phenylselenido)-2,7,9,9-tetramethylacridan (H[ASe 2 Ph2 ] ( 2 )), were deprotonated with one equiv of n BuLi to afford dimeric lithium complexes [Li(AE 2 Ph2 )] 2 (E = S ( 3 ), Se ( 4 )) or with one equiv of KCH 2 Ph to afford the previously reported potassium complexes [K(AS 2 Ph2 )(dme)] x ( 5 ) and [K(ASe 2 Ph2 )(dme) 2 ] ( 6 ). Attempts to prepare a direct telluroether analogue of compounds 1 – 2 were unsuccessful. However, the bulky selenoether- and telluroether-containing pro-ligands 4,5-bis(2,4,6-triisopropylphenylselenido)-2,7,9,9-tetramethylacridan (H[ASe 2 Tripp2 ] ( 7 )) and 4,5-bis(2,4,6-triisopropylphenyltellurido)-2,7,9,9-tetramethylacridan (H[ATe 2 Tripp2 ] ( 8 )) were accessed via the reaction of 4,5-dibromo-2,7,9,9-tetramethylacridan with three equiv of n BuLi, followed by the addition of two equiv of the corresponding diaryl dichalcogenide and quenching with dilute HCl (aq) . The new selenoether- and telluroether-containing pro-ligands were subsequently deprotonated using KCH 2 Ph to afford [K(AE 2 Tripp2 )(dme) 2 ] (E = Se ( 9 ), Te ( 10 )). Compounds 1 – 10 were characterized by 1 H, 13 C{ 1 H}, 77 Se{ 1 H}, 125 Te{ 1 H}, and 7 Li NMR spectroscopy, where applicable, and single-crystal X-ray structures were obtained for all lithium and potassium complexes ( 3 – 6 and 9–10 ). DFT calculations were also performed to assess the nature of bonding between the hard group 1 cations and the soft chalcogenoethers.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".