Inter- and Intramolecular Temperature-Dependent Vibrational Perturbations of Alkanethiol Self-Assembled Monolayers
Bibliographic record
Abstract
The infrared spectra of octanethiol, dodecanethiol, and hexadecanethiol (C 8, C 12, and C 16, respectively) monolayers adsorbed on Au(111) textured surfaces have been explored in the 25−300 K regime. The C−H stretching modes typically shift by several wavenumbers to lower frequencies and the intensities increase by as much as 75% as the temperature is decreased, providing evidence of, among other effects, the coupling of these stretching modes with lower energy vibrational modes. In contrast, for all temperatures below 300 K, the positions of the C−H bands of fully hydrogenated C 16 shift by several wavenumbers to higher frequencies as the hydrogenated adsorbates are increasingly diluted in a matrix of fully deuterated C 16, showing that all bands are subject to intermolecular couplings. The analysis of the behavior of the C−H stretching bands suggests that the temperature dependence of the vibrational frequencies associated with the methylene stretching modes is principally due to intermolecular couplings, whereas the temperature dependence of the vibrations associated with the methyl terminations is largely due to intramolecular couplings. It is suggested that the highly constrained geometry of the isotopically diluted monolayer may provide an environment that is less sensitive to intramolecular couplings with low-frequency modes than that of urea−clathrate-isolated species.
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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 | 0.000 |
| 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) | 0.000 | 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".