Theoretical investigation of the oxidation pathways of HO<sup>•</sup>-initiated reactions of acrolein, methacrolein, and <i>trans</i>-crotonaldehyde
Bibliographic record
Abstract
Ab initio molecular-orbital calculations have been performed to investigate the reaction mechanisms of the HO • -initiated reactions of the α,β-unsaturated aldehydes: acrolein (ACR), methacrolein (MACR), and trans-crotonaldehyde (CROT). All geometries were fully optimized at the MP2(Full)/6–31G(d,p) level. The correlation energy corrections were introduced by carrying out single-point calculations using both spin-projected second-order Møller–Plesset perturbation theory (PMP2) and coupled-cluster theory (CCSD(T)) using basis sets of different sizes. All reaction pathways studied proceed via a barrierless formation of a loosely bound pre-reactive complex in the entrance channel. The transition-state structures of the HO • additions to the terminal (β) and to the central (α) carbon atoms of the C=C double bond are found to be reactant-like structures. The lowest-energy barrier pathways are found to be the aldehydic H-atom abstraction. The β-addition pathways are found to be energetically more favored than the α-addition pathways. The HO • addition and aldehydic H-atom abstraction pathways are found to be highly exoergic, with the H-atom abstraction pathway being more exoergic than the addition pathways. Although the methyl substitution at the C=C double bond of methacrolein and crotonaldehyde lowers the energies of the transition-state structures of both α- and β-addition pathways, it destabilizes the energies of the transition-state structures of the corresponding aldehydic H-atom abstraction pathways, compared with that of acrolein.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| 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".