Determination of the crystal structure of three organic compounds by X-ray diffraction
Bibliographic record
Abstract
The crystal structure of dibenzothiophene has been determined by X-ray diffraction. Mo-Kα [subscript omitted] scintillation counter data were used for this analysis; the sulfur atom position was determined by means of a Patterson function; the carbon atoms were located from a Fourier synthesis, and the hydrogen atoms, from a difference synthesis. Refinement of positional and thermal parameters was by least-squares methods. The molecule is slightly folded, the dihedral angles between the five-membered ring and the six-membered rings being 0.4° and 1.2°. The bond distances and valency angles are similar to those in related molecules. The C-S bond length is 1.740 A, and the C-S-C angle is 91.5°. The crystal structure of DL-ornithine hydrobromide has been determined by means of visual Cu-Kα [subscript omitted] data. The bromine ion position was found by Patterson methods; carbon, nitrogen, and oxygen atoms were located on Fourier summations and the hydrogen atoms, on a difference synthesis. The positional and thermal parameters were refined by least-squares. The ornithine molecule is a zwitterion, with both nitrogens accepting protons. The mean bond distances are C-0, 1.249 A; C-N, 1.469 A; C-C, 1.532 A. The structure is held together by a system of N—H …… 0 (2.84, 2.84, 2.89 A) and N—H…..Br (3.29, 3.36,.3.46 A) hydrogen bonds. The crystal and molecular structure of histamine diphosphate monohydrate has been determined with scintillation counter Mo-Kα [subscript omitted] data. The positions of the phosphorus atoms were determined by Patterson methods; the carbon, nitrogen and oxygen atoms were located by means Fourier syntheses; the hydrogen atoms were found on a difference synthesis. The thermal and positional parameters were refined by least-squares. The atoms of this histamine cation lie in two almost perpendicular planes, the plane of the imidazole ring and that of the side chain. The bond lengths and angles are similar to the corresponding values in histidine hydrochloride monohydrate. The dimensions of the two P0₂(OH) ₂⁻ ions are P-0 1.51 A, P-OH 1.57 A, O-P-0 115.5°, and HO-P-OH 107.0°. The most important feature of the packing is a complex system of 0-H.....0 and N-H...0 hydrogen bonds.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.007 | 0.003 |
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".