Structure and chain polarization of long polyynes investigated with infrared and Raman spectroscopy
Bibliographic record
Abstract
Symmetrically and unsymmetrically endcapped polyynes (triisopropylsilyl – TIPS – and super trityl endcapping groups) have been studied with density functional theory calculations and Raman and infrared spectroscopy. This spectroscopic investigation provides general guidelines for studying the vibrational and structural features of sp‐carbon‐based materials, which nowadays are at the center of growing interest for the potential applications of nanostructured carbon materials in molecular electronics. On the basis of the description of CC stretching modes of polyynes in terms of longitudinal optical phonons of the parent infinite sp‐carbon chain, we have carried out the complete assignment of the observed infrared and Raman features in the 2300–1900 cm −1 range, for chain lengths in the range 4–20 triple bonds. This allows demonstration of polarization effects induced by an unsymmetric structure and deviations from chain linearity in long polyynes. Copyright © 2013 John Wiley & Sons, Ltd.
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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".