Coordination and hydrogen bonded networks featuring 4,4′-dicarboxy-2,2′-bipyridine (H2dcbp): structural characterisation of H2dcbp, [Co(dcbp)(H2O)4]·4H2O, and {[Cu(dcbp)(H2O)2]·2H2O}n
Bibliographic record
Abstract
We report herein the single crystal structures of 4,4′-dicarboxy-2,2′-bipyridine, H2dcbp, and two complexes it forms with Co(II), [Co(dcbp)(H2O)4]·4H2O, 1, and Cu(II), {[Cu(dcbp)(H2O)2]·2H2O}n, 2. H2dcbp adopts the anti conformation in the solid-state, with a dihedral angle of 148° between each pyridyl ring. Face-to-face π⋯π interactions reinforce intermolecular hydrogen bonding (O–H⋯N) involving both carboxylate oxygen and pyridyl nitrogen atoms forming a 2D inter-helical network. Alternate 2D layers are of opposite chirality and are linked into 3D through (C–H⋯O) hydrogen bonds. In both 1 and 2 the ligand is deprotonated giving neutral complexes with 1 ∶ 1 stoichiometry. Although 1 is monomeric, extensive hydrogen bonding between the deprotonated carboxylates, lattice water, and coordinated water molecules results in a 3D network which also contains face-to-face π⋯π interactions between adjacent dcbp ligands. Within 2, pseudo-octahedral coordination about the Cu(II) centre is furnished by bidentate bipyridyl nitrogens, two monodentate carboxylates (from two adjacent dcbp ligands) and two water molecules. Coordination of dcbp in this instance forms a 2D coordination polymer, which is further linked by extensive hydrogen bonding between carboxylates and water molecules, giving a 3D network.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 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 teacher head, 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".