Structural characterization of silver dialkylphosphite salts using solid‐state <sup>109</sup>Ag and <sup>31</sup>P NMR spectroscopy, IR spectroscopy and DFT calculations
Bibliographic record
Abstract
High-resolution solid-state (109)Ag and (31)P NMR spectroscopy was used to investigate a series of silver dialkylphosphite salts, Ag(O)P(OR)(2) (R = CH(3), C(2)H(5), C(4)H(9) and C(8)H(17)), and determine whether they adopt keto, enol or dimer structures in the solid state. The silver chemical shift, CS, tensors and |J((109)Ag, (31)P)| values for these salts were determined using (109)Ag (Xi = 4.652%) NMR spectroscopy. The magnitudes of J((109)Ag, (31)P) range from 1250 +/- 10 to 1318 +/- 10 Hz and are the largest reported so far. These values indicate that phosphorus is directly bonded to silver for all these salts and thus exclude the enol structure. All (31)P NMR spectra exhibit splittings due to indirect spin-spin coupling to (107)Ag (I = 1/2, NA = 51.8%) and (109)Ag (I = 1/2, NA = 48.2%). The (1)J((109)Ag, (31)P) values measured by both (109)Ag and (31)P NMR spectroscopy agree within experimental error. Analysis of (31)P NMR spectra of stationary samples for these salts allowed the determination of the phosphorus CS tensors. The absence of characteristic P=O stretching absorption bands near 1250 cm(-1) in the IR spectra for these salts exclude the simple keto tautomer. Thus, the combination of solid-state NMR and IR results indicate that these silver dialkylphosphite salts probably have a dimer structure. Values of silver and phosphorus CS tensors as well as (1)J((109)Ag, (31)P) values for a dimer model calculated using the density functional theory (DFT) method are in agreement with the experimental observations.
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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".