Zinc halide oxazoline complexes — The quest for structural diversity
Bibliographic record
Abstract
The synthesis and characterization of 14 ZnX2 (X = Cl or Br) complexes containing aryl-oxazoline (ox) ligands is reported. Eleven of these derivatives have been structurally elucidated in the solid state by single crystal X-ray diffraction methods. The ligands used are 2-(3-R-phenyl)-2-oxazoline (R = Cl or Me), 2-(4-R-phenyl)-2-oxazoline (R = Cl, F, Me or –OMe), and 2-(anisol-2-yl)-4,4-dimethyl-2-oxazoline (7a). All oxazolines, with the exception of 7a, lead to the formation of materials identified as ZnX2(ox)2 upon reaction with ZnX2. A distorted tetrahedral coordination motif around the Zn metal centre is displayed in nine examples that have been characterized by single crystal X-ray diffraction methods. In the case of ligand 7a, an unusual dimeric species (X-ray) of formula [ZnCl2(7a)]2 (7b) is formed upon reaction with ZnCl2. Compound 7b displays a rare (formally neutral) µ-(Cl)2-(Zn[L]Cl)2 (L = neutral donor ligand) unit in addition to secondary bonding interactions between the Zn centres and the O-atom of the –OMe group (Zn···O distance of ~2.56 Å). In contrast, reactions of 7a with ZnBr2 lead to the formation of a monomeric species containing a chelating molecule of 7a with binding through the oxazoline N-atom and the methoxy (Zn–O distance of ~2.14 Å) group, i.e., ZnBr2(7a-κ2N,OOMe). These complexes are discussed in terms of structurally related Zn species and some comment is made as to the direction to be explored within this series of materials that may lead to further unusual structural diversity.Key words: oxazoline, oxazole, zinc, X-ray crystal structure, coordination complex, Zn(II) halide.
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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 | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| 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".