The Role of Hydrogen Bonds in Facilitating Planar Alignment of Mn(II) Halide 2,6-Bis(benzimidazole)pyridine-Based Complexes
Bibliographic record
Abstract
A series of Mn(II) halide complexes has been synthesized with 2,6-bis(benzimidazole)-pyridine (BBP), 2,6-bis( N -methyl-benzimidazole)pyridine (MBBP), and 2,6-bis(benzathiazole)-pyridine (BBTP) ligands in solvents capable of acting as hydrogen bonding donors and/or acceptors, resulting in Mn(BBP)(EtOH)X 2 (X = Cl, Br), Mn(BBP)Br 2 ·DMF, Mn(BBP)Br 2 ·MeCN, Mn(MBBP)X 2 (X = Cl, Br), [Mn(MBBP)(Br)(MeOH) 2 ][Br] and Mn(BBTP)X 2 (X = Cl, Br). The crystal structures of these materials were analyzed for the degree of planar packing of the anisotropic ligands. The exchange of hydrogen bonding donor and acceptor solvents (ethanol) for solvents only capable of accepting hydrogen bonds (DMF, acetonitrile) decreased the role of the solvent in the hydrogen bonding networks and also capped the NH groups of BBP, reducing the effectiveness of the BBP to form extended networks. Replacing NH groups in BBP with N -methyl groups (MBBP) and sulfur (BBTP) reduced the number of strong interactions between complexes, leading to a greater tendency for nonplanar crystal packing of the ligands. The effect of poorly oriented anisotropic ligands within the structures results in lower birefringence (Δ n ) values of 0.229(10) and 0.23(3) for Mn(BBP)Cl 2 ·DMF and Mn(MBBP)Br 2, respectively. Compounds Mn(BBP)(EtOH)X 2 (X = Cl, Br) were found to have good stacking of BBP units, leading to a highly anisotropic structure and a Δ n value of 0.538(3) for Mn(BBP)(EtOH)Br 2 .
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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 | 0.000 |
| 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".