A solid-state <sup>133</sup>Cs nuclear magnetic resonance and X-ray crystallographic study of cesium complexes with macrocyclic ligands
Bibliographic record
Abstract
We report solid-state NMR determination of the 133Cs chemical shift anisotropy (CSA) for a series of cesium complexes with macrocyclic ligands. It was found that the isotropic 133Cs chemical shifts are related to the number of oxygen atoms to which the Cs+ ion is coordinated. The 133Cs chemical shifts were found to correlate with average Cs-O distances. We also attempt to use the established correlation to deduce Cs+ coordination environment for compounds with unknown structures. We also report the X-ray determination of the crystal structure for Cs(DB18C6)2SCN1/2CH3OH1/2H2O. The compound crystallizes in monoclinic, a = 14.503(2), b = 15.152(3), c = 39.989(6) Å, β = 90.796(8)°, space group P21/c, Z = 8. There are two independent molecules in the asymmetric unit cell where each of the two Cs+ ions is coordinated to two DB18C6 ligand molecules forming a sandwich-type structure.Key words: solid state NMR, alkali metal, 133Cs chemical shift, macrocyclic ligand, crystal structure.
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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".