Coordination Chemistry of α‐ω‐Bis(pyridylimine) Ligands Containing Flexible Linkers with Copper(I)
Bibliographic record
Abstract
Abstract Copper(I) complexes of a series of six potentially tetradentate bis(pyridylimine) ligands were prepared, where the pyridylimine groups were separated by different linking units [in L1, CH2CH2CH2(SiMe2O)20SiMe2CH2CH2CH2; in L2, CH2CH2CH2SiMe2OSiMe2CH2CH2CH2; in L3, CH2CH2; in L4, CH2(CH2)4CH2; in L5, CH2(CH2)7CH2; in L6, CH2CH2CH2OCH2CH2OCH2CH2OCH2CH2CH2]. The solubilities of L1, L2 and [Cu(L2)](PF6) in supercritical carbon dioxide were determined. The coordination chemistry of L1–L2 with CuI was studied by UV/Vis, multinuclear NMR and IR spectroscopy, MALDI‐TOF and ESI mass spectrometries and elemental analysis. These data suggested that [1+1] complexes had formed. Dicopper complexes of L3–L6 were prepared for comparison, and [Cu2(L5)2](PF6)2 characterized by single‐crystal X‐ray diffraction analysis. Close methylene C–H···π interactions are observed within the structure. PGSE NMR spectroscopy was used to determine the hydrodynamic radii of the species in solution and comparison of these data with computational models for the complexes was made. Freezing point depression measurements afforded molecular weights for solution‐state species in agreement with the formulations proposed via NMR and mass spectrometric data. There is no evidence to support linear metallopolymer formation but data suggest that [2+2] and [1+1] metallomacrocyles were formed, with siloxane linking groups encouraging the formation of [1+1] species. Solid‐state NMR spectroscopic data on [Cu(L1)](PF6) indicate the presence of two different environments for the PF6– anions.
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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 | 0.000 | 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".