Dihydrogen Activation by B(<i>p</i>-C<sub>6</sub>F<sub>4</sub>H)<sub>3</sub> and Phosphines
Bibliographic record
Abstract
The Grignard reagent ( p -C 6 F 4 H)MgCl was used to prepare (Et 2 O)B( p -C 6 F 4 H) 3 ( 2 ) and the free borane B( p -C 6 F 4 H) 3 ( 1 ). On the basis of Lewis acidity tests, the borane 1 exhibits ca. 95% of the acidity of B(C 6 F 5 ) 3 . 1 forms classical adducts with ethers and phosphines of the general formula (L)B( p -C 6 F 4 H) 3 (L = Et 2 O ( 2 ), THF ( 3 ), Me 3 P ( 4 ), Et 3 P ( 5 ), i -Pr 2 (H)P ( 6 ), Ph 3 P ( 7 ), (3,5-Me 2 C 6 H 3 ) 3 P ( 8 ), t -Bu 2 (H)P ( 9 ), and Cy 3 P ( 10 )). Compounds 9 and 10 react with 4 atm of H 2 to give the salts [ t -Bu 2 PH 2 ][HB( p -C 6 F 4 H) 3 ] ( 11 ) and [Cy 3 PH][HB( p -C 6 F 4 H) 3 ] ( 12 ). The sterically demanding phosphines R 3 P (R = t -Bu, i -Pr, 2,4,6-Me 3 C 6 H 2, and 2-MeC 6 H 4 ), R 2 R′P (R,R′ = t -Bu, i -Pr and t -Bu, Cy), and (Ph 2 CH)R 2 P (R = t -Bu ( 22 ), i -Pr ( 23 ), Cy ( 24 ), and C 5 H 9 ( 25 )) show no evidence of adduct formation with 1, but react with H 2 to give the corresponding salts [R 3 PH][HB( p -C 6 F 4 H) 3 ] ( 13 − 16 ), [R 2 R′PH][HB( p -C 6 F 4 H) 3 ] ( 17 − 20 ), and [(Ph 2 CH)R 2 PH][HB( p -C 6 F 4 H) 3 ] ( 26 − 29 ), respectively. The [ t -Bu 2 PH 2 ] + species 11 is stable only under an H 2 overpressure, while the [ t -Bu 3 PH] + salt 13 cleanly extrudes isobutene and H 2 at elevated temperatures to give 9 . The [(2-MeC 6 H 4 ) 3 PH] + derivative 16 readily liberates H 2 under vacuum, thus providing a metal-free system capable of reversible H 2 uptake and release. Crystallographic data for compounds 1, 5, 8, 9, 10, 13, and 26 are reported.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| 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; both teacher heads agree on what is shown here.
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".