Evidence for the Participation of Excited Electronic States in the Unimolecular Dissociation Reactions of Ionic Complexes between NO and Aromatic Compounds
Bibliographic record
Abstract
The nitrosation of aromatic molecules A (where A=benzonitrile, benzene, pyridine, furan and thiophene) has been investigated by tandem mass spectrometry. The unimolecular dissociation of metastable ionic complexes generated by NO chemical ionization of benzonitrile changes as a function of ion source pressure. As the NO concentration in the source increases, the metastable ion (MI) mass spectrum goes from being dominated by NO + to one dominated by ionized benzonitrile and its fragmentation products. This can only be explained by the formation of an excited-state complex in the source [formed when NO + (a 3 Σ + ) binds to benzonitrile] that can dissociate to form high internal energy ionized benzonitrile. A similar result is observed when A=pyridine. When A=benzene, the MI mass spectrum is dominated by ionized benzene, a result that is consistent with the adiabatic dissociation of the ground singlet-state of the complex, provided that electron transfer between the two members of the complex is slow compared with the microsecond timescale of the experiments. If fast exchange does occur, as is suggested by theoretical calculations of the complex, then the lowest energy triplet-state must be co-produced in the ion source. The MI mass spectra of the complexes involving furan and thiophene are consistent with the dissociation of the lowest energy singlet-state.
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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) | 0.000 | 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".