Proof of Concept Studies Directed Towards Designed Molecular Wires: Property‐Driven Synthesis of Air and Moisture‐Stable Polystannanes
Bibliographic record
Abstract
Abstract Polystannanes with azobenzene moieties designed to protect the Sn–Sn backbone from light‐ and moisture‐induced degradation are described. The azo‐stannyl precursor 3 (70 %) is converted in good yields (88–91 %) to the mono‐ ( 4 ), and dichlorostannanes ( 5 ), by sequential chlorination, followed by further reduction of 5 to the dihydride ( 6 ) using NaBH 4 (78 %). All stannanes were characterised by NMR ( 1 H, 13 C, 119 Sn) spectroscopy and HRMS; in addition, 3 , 4 and 5 were structurally elucidated using X‐ray diffraction analysis. Metal‐free dehydrocoupling of 6 at RT leads exclusively to homopolymer ( 7 ‐ i ) displaying an initial solution 119 Sn NMR signal ( δ =−196 ppm) that migrates to −235 ppm after 10 days ( 7 ‐ f ). In contrast, metal‐catalyzed dehydrocoupling of 6 in toluene at RT leads directly 7 ‐ f . Random co‐polymers formed from 6 and ( n Bu) 2 SnH 2 at 4:1 ( 8 a ) and 1:1 ( 8 b ) ratios were compared to the alternating polystannane ( 9 ) prepared by the reaction of 6 with ( n Bu) 2 Sn(NEt 2 ) 2 . DFT calculations of 3 – 6 indicate that hypercoordination at Sn is influenced by substituents and by solvation. Homopolymer 7 was found to have unprecedented moisture and light stability in the solid state for >6 months.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| 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 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".