Superparamagnetic Ceramic Nanocomposites: Synthesis and Pyrolysis of Ring-Opened Poly(ferrocenylsilanes) inside Periodic Mesoporous Silica
Bibliographic record
Abstract
[1]Silaferrocenophanes fcSiMe 2 ( 1 ) and fcSi(CH 2 ) 3 ( 3 ) (fc = Fe(η 5 -C 5 H 4 ) 2 ) were incorporated into the well-ordered, hexagonal channels of mesoporous silica (MCM-41). Characterization of the composite materials indicates the presence of ring-opened monomer, oligomer, and polymer, and, in the case of 1, also free monomer. Polymerization of monomer 1 inside the channels of MCM-41 was demonstrated by DSC. However, in the case of 3 only the ferrocenophane ring was completely opened, and the silacyclobutane ring was mostly intact. When pyrolyzed at 900 °C in a nitrogen atmosphere, the mesoporous silica/ferrocenylsilane composites formed Fe nanoparticles in the ca. 30−40 Å channels of MCM-41. Characterization of the magnetic properties of the product formed when 1 is pyrolyzed in the channels of mesoporous silica indicated that the clusters were superparamagnetic. Magnetization versus field data at 300 K were fit to a sum of two Langevin functions, implying the presence of two distinct magnetic phases. From the magnetization data, the two phases are best described as Fe nanoparticles with diameters of 50−64 Å coated with a thin (ca. 4−6 Å) oxide layer. The product obtained from the pyrolysis of poly(ferrocenylsilane) 2 in the channels of MCM-41 contains much smaller Fe particles than those observed in a pyrolysis of bulk 2, indicating that the silica channels affect the nucleation and growth of the Fe nanoparticles.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| 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".