Ab Initio/RRKM Study of Dissociation Mechanism of Benzene Trication
Bibliographic record
Abstract
Density functional B3LYP /6-31 G (d,p) calculations have been performed in order to investigate isomerization and dissociation of [Formula: see text] in the ground electronic state, which are relevant to the Coulomb explosion mechanism of benzene. The results demonstrate that the benzene-like isomer of [Formula: see text], 1, can decompose through various pathways leading to distinct fragmentation products. The most kinetically favorable channel involves ring opening in 1 accompanied with 1,2-shifts of two hydrogen atoms followed by rotation around the middle C–C bond and dissociation to H 2 CCCH 2+ + H 2 CCCH + with exothermicity and the highest barrier of 100.2 and 38.4 kcal/mol, respectively. Several other product channels, including [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text], share the same highest barrier for the initial ring opening step with the pathway producing H 2 CCCH 2+ + H 2 CCCH + but exhibit higher second highest barriers. Elimination of [Formula: see text] to form [Formula: see text] is 137.9 kcal/mol exothermic but the highest barrier on the pathway leading to these products is 53.0 kcal/mol. A simple proton elimination to produce [Formula: see text] is computed to be 82–84 kcal/mol exothermic and to depict a 64–65 kcal/mol barrier. RRKM calculations of rate constants for individual reaction steps assuming that the initial internal energy of 1 is 110 kcal/mol and solving kinetic master equations to obtain relative branching ratios show that H 2 CCCH 2+ + H 2 CCCH + are the dominant products (81.5%) followed by [Formula: see text] (13.2%) and the other minor products include [Formula: see text] (2.6%), [Formula: see text] (1.1%), [Formula: see text] (0.55%), [Formula: see text] (0.49%), [Formula: see text] (0.20%), and [Formula: see text] (0.14%). The fragments are expected to be produced with high translational energy due to high Coulomb repulsion energy barriers.
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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".