<sup>127</sup>I Solid‐State NMR Spectroscopy of Organic Periodates Featuring Halogen Bonded IO<sub>4</sub><sup>−</sup> ⋅ ⋅ ⋅ IO<sub>4</sub><sup>−</sup> Adducts
Bibliographic record
Abstract
Abstract Hydroxyanions and oxyanions can overcome electrostatic repulsion between like charges to form supramolecular architectures whose formation is driven by non‐covalent interactions such as hydrogen bonds and halogen bonds (HaB). We report here a 127 I solid‐state nuclear magnetic resonance (SSNMR) study of a series of six organic periodates including compounds which feature I ⋅ ⋅ ⋅ O HaB between pairs of IO 4 − anions and control samples which do not feature HaB. 127 I SSNMR spectra of powdered samples acquired under stationary conditions at 9.4, 11.7, and 21.1 T are simulated using an exact diagonalization of the Zeeman‐quadrupolar Hamiltonian to provide the isotropic chemical shift, 127 I nuclear quadrupolar coupling constant ( C Q ), and quadrupolar asymmetry parameter for each compound. One of the HaB compounds, 4‐(pyrrolidin‐1‐yl)pyridinium periodate, is characterized by the largest C Q ( 127 I) value measured to date for a periodate anion, 52.70 MHz. Control organic periodates which do not have HaBs have C Q ( 127 I) values that are much lower than those seen in the halogen‐bonded systems, thereby easily differentiating between these two sets of compounds. The C Q ( 127 I) values for those compounds featuring only halogen‐bonded periodate anions correlate with the shear strain of the anion, which may be attributed to the influence of the HaB on the local geometry. More rigorous correlations between structure and the 127 I NMR data are confounded by the presence of dynamics in some of the samples.
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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) | 0.002 | 0.002 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.002 | 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".