Crystal structures of 3-chloro-2-nitrobenzoic acid with quinoline derivatives: 3-chloro-2-nitrobenzoic acid–5-nitroquinoline (1/1), 3-chloro-2-nitrobenzoic acid–6-nitroquinoline (1/1) and 8-hydroxyquinolinium 3-chloro-2-nitrobenzoate
Bibliographic record
Abstract
The structures of three compounds of 3-chloro-2-nitrobenzoic acid with 5-nitroquinoline, (I), 6-nitroquinoline, (II), and 8-hydroxyquinoline, (III), have been determined at 190 K. In each of the two isomeric compounds, (I) and (II), C7H4ClNO4·C9H6N2O2, the acid and base molecules are held together by O—H...N and C—H...O hydrogen bonds. In compound (III), C9H8NO+·C7H3ClNO4 −, an acid–base interaction involving H-atom transfer occurs and the H atom is located at the N site of the base molecule. In the crystal of (I), the hydrogen-bonded acid–base units are linked by C—H...O hydrogen bonds, forming a tape structure along the b-axis direction. Adjacent tapes, which are related by a twofold rotation axis, are linked by a third C—H...O hydrogen bond, forming wide ribbons parallel to the (\overline{1}03) plane. These ribbons are stacked via π–π interactions between the quinoline ring systems [centroid–centroid distances = 3.4935 (5)–3.7721 (6) Å], forming layers parallel to the ab plane. In the crystal of (II), the hydrogen-bonded acid–base units are also linked into a tape structure along the b-axis direction via C—H...O hydrogen bonds. Inversion-related tapes are linked by further C—H...O hydrogen bonds to form wide ribbons parallel to the (\overline{3}08) plane. The ribbons are linked by weak π–π interactions [centroid–centroid distances = 3.8016 (8)–3.9247 (9) Å], forming a three-dimensional structure. In the crystal of (III), the cations and the anions are alternately linked via N—H...O and O—H...O hydrogen bonds, forming a 21 helix running along the b-axis direction. The cations and the anions are further stacked alternately in columns along the a-axis direction via π–π interactions [centroid–centroid distances = 3.8016 (8)–3.9247 (9) Å], and the molecular chains are linked into layers parallel to the ab plane through these interactions.
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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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".