Crystal structures of the two isomeric hydrogen-bonded cocrystals 2-chloro-4-nitrobenzoic acid–5-nitroquinoline (1/1) and 5-chloro-2-nitrobenzoic acid–5-nitroquinoline (1/1)
Bibliographic record
Abstract
The structures of two isomeric compounds of 5-nitroquinoline with chloro- and nitro-substituted benzoic acid, namely, 2-chloro-4-nitrobenzoic acid–5-nitroquinoline (1/1), (I), and 5-chloro-2-nitrobenzoic acid–5-nitroquinoline (1/1), (II), both C7H4ClNO4·C9H6N2O2, have been determined at 190 K. In each compound, the acid and base molecules are held together by an O—H...N hydrogen bond. In the crystal of (I), the hydrogen-bonded acid–base units are linked by a C—H...O hydrogen bond, forming a tape structure along [1\overline{2}0]. The tapes are stacked into a layer parallel to the ab plane via N—O...π interactions between the nitro group of the base molecule and the quinoline ring system. The layers are further linked by other C—H...O hydrogen bonds, forming a three-dimensional network. In the crystal of (II), the hydrogen-bonded acid–base units are linked into a wide ribbon structure running along [1\overline{1}0] via C—H...O hydrogen bonds. The ribbons are further linked via another C—H...O hydrogen bond, forming a layer parallel to (110). Weak π–π interactions [centroid–centroid distances of 3.7080 (10) and 3.7543 (9) Å] are observed between the quinoline ring systems of adjacent layers. Hirshfeld surfaces for the 5-nitroquinoline molecules of the two compounds mapped over shape index and d norm were generated to visualize the weak intermolecular interactions.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".