An acidity scale of phosphonium tetraphenylborate salts and ruthenium dihydrogen complexes in dichloromethane
Bibliographic record
Abstract
Equilibrium constants (K DM ) for reactions between acids and bases of the title compounds in CD 2 Cl 2 (DM) have been determined by 31 P and 1 H NMR spectroscopy at room temperature. [HPCy 3 ]BPh 4 and [HPCy 3 ]BF 4 , with pK DM assigned by literature convention to 9.7, have been used as the anchor compounds for the pK DM determinations. A continuous scale of pK DM values covering the range 9.7 to 5.7 is created with the acidic compounds [HPR 3 ]BPh 4 . Those acids with pK DM greater than 6 are stable, while those with more acidic cations HPR 3 + protonate BPh 4 to produce R 3 PBPh 3 and benzene. The literature pK THF values reported for [HPBu 2 Ph]BPh 4 , [HPMePh 2 ]BPh 4 , and [HPEtPh 2 ]BPh 4 are questionable because of this protonation reaction. NOE and PGSE 1 H NMR techniques are used to show that [HPCy 2 Ph]BPh 4 in DM exists as ion pairs and higher aggregates up to quadrupoles at the concentrations used in the acidbase studies. The new dihydrogen complexes [Ru(H 2 )Cl(PPh 3 ) 2 (dach)]BF 4 (dach = (1R,2R)-()-diaminocyclohexane) and [Ru(H 2 )Cl{tmeP 2 (NH) 2 }]BF 4 (tmeP 2 (NH) 2 = PPh 2 C 6 H 4 CH 2 NHCMe 2 CMe 2 NHCH 2 C 6 H 4 PPh 2 ) were prepared by reaction of RuHCl(PPh 3 ) 2 (dach) and RuHCl{tmeP 2 (NH) 2 } with HBF 4 . Their crystal structures are reported, and the pK DM values of their BPh 4 salts were determined to be 8.6 and 6.9, respectively.Key words: acidity, dihydrogen complex, hydride, phosphonium, dichloromethane.
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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) | 0.001 | 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; 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".