Infrared photodissociation spectroscopy of Si<sup>+</sup>(CO<sub>2</sub>)<i><sub>n</sub></i> and Si<sup>+</sup>(CO<sub>2</sub>)<i><sub>n</sub></i>Ar complexes Evidence for unanticipated intracluster reactions
Bibliographic record
Abstract
Si+(CO2)n and Si+(CO2)nAr ionmolecule complexes were produced by laser vaporization in a pulsed supersonic expansion. The ions were mass-selected in a reflectron time-of-flight spectrometer and studied with infrared photodissociation spectroscopy near the asymmetric stretch vibration of CO2. Si+(CO2)n clusters fragment by the loss of CO2 whereas Si+(CO2)nAr complexes fragment by the loss of argon. All clusters have resonances near the CO2 asymmetric stretch, but with shifts in frequency that are size dependent. The patterns seen in the small clusters are consistent with electrostatic bonding, while the larger systems provide evidence for an intracluster reaction forming oxide-carbonyl species. Density functional theory was employed to examine the structures of these clusters, and their calculated vibrational frequencies were compared to the measured values. Ligand assembly in Si+(CO2)n complexes is dominated by the presence of the occupied 3p valence orbital of the silicon cation. Key words: ionmolecule complexes, infrared spectroscopy, photodissociation, density functional theory.
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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".