Crystal structure of 4-chloro-2-nitrobenzoic acid with 4-hydroxyquinoline: a disordered structure over two states of 4-chloro-2-nitrobenzoic acid–quinolin-4(1<i>H</i>)-one (1/1) and 4-hydroxyquinolinium 4-chloro-2-nitrobenzoate
Bibliographic record
Abstract
The title compound, C 9 H 7.5 NO·C 7 H 3.5 ClNO 4 , was analysed as a disordered structure over two states, viz . co-crystal and salt, accompanied by a keto–enol tautomerization in the base molecule. The co-crystal is 4-chloro-2-nitrobenzoic acid–quinolin-4(1 H )-one (1/1), C 7 H 4 ClNO 4 ·C 9 H 7 NO, and the salt is 4-hydroxyquinolinium 4-chloro-2-nitrobenzoate, C 9 H 8 NO + ·C 7 H 3 ClNO 4 − . In the compound, the acid and base molecules are held together by a short hydrogen bond [O...O = 2.4393 (15) Å], in which the H atom is disordered over two positions with equal occupancies. In the crystal, the hydrogen-bonded acid–base units are linked by N—H...O and C—H...O hydrogen bonds, forming a tape structure along the a- axis direction. The tapes are stacked into a layer parallel to the ab plane via π–π interactions [centroid–centroid distances = 3.5504 (8)–3.9010 (11) Å]. The layers are further linked by another C—H...O hydrogen bond, forming a three-dimensional network. Hirshfeld surfaces for the title compound mapped over shape-index and d norm were generated to visualize the intermolecular interactions.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.002 | 0.002 |
| Meta-epidemiology (broad) | 0.003 | 0.001 |
| Bibliometrics | 0.002 | 0.004 |
| Science and technology studies | 0.001 | 0.004 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.004 | 0.002 |
| Research integrity | 0.002 | 0.003 |
| 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; 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".