Frustrated and Realized Hydrogen Bonding in 4-Hydroxy-3,5-di<i>tert</i>butylphenylphosphine Derivatives
Bibliographic record
Abstract
Synthesis and molecular and supramolecular structures of a series of triarylphosphines P(Ph) 3– n {4-RO-3,5-( t Bu) 2 -C 6 H 2 } n ( n = 1, 3; R = SiMe 3, H) are reported. Chemical oxidation products E=P(Ph) 3– n {4-RO-3,5-( t Bu) 2 -C 6 H 2 } n (E = O, S, and Se; n = 1, 3; R = SiMe 3, H) are also reported. Crystal structures of the reported compounds were determined by single-crystal X-ray diffraction, using a Hirshfeld atom refinement with NoSpherA2 through OLEX2, which provides an average improvement in C–C bond distance precision of 35%. Phosphine basicity for the phosphines with n = 1, R = H and n = 3, R = SiMe 3, H was determined using the 1 J P,Se values of the respective selenides; 1 J P,Se = 699 Hz for E = Se, n = 3, and X = H identifies the most basic triarylphosphine ever reported. Intermolecular interactions allow classification of the 17 structures into 4 categories: those with only dispersion-induced short contacts, those with frustration of H-bonding, those with only classic H-bonding, and those with combinations of classic and frustration of H-bonding. A “double phenol embrace” classified by an R 2 2 (4) graph set is a weak intermolecular synthon organizing lattices with 2,6-di tert butylphenol functional groups. Classic H-bonding occurs only when E = O.
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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) | 0.000 | 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 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".