Stereoelectronic interaction effects on the conformational properties of 5-methyl-5-aza-1,3-dithiacyclohexane and its analogous containing N, P, O, and Se atoms — A hybrid density functional theory (DFT), ab initio study, and natural bond orbital (NBO) analysis
Bibliographic record
Abstract
Natural bond orbital (NBO) analysis, hybrid density functional theory (hybrid DFT: B3LYP/6-311+G**//B3LYP/6-311+G**), and ab initio molecular orbital (MO: MP2/6-311+G**//B3LYP/6-311+G**) based methods were used to study the electronic delocalization energy (DE), dipole–dipole interactions, and steric repulsions on the conformational properties of 5-methyl-5-aza-1,3-dioxacyclohexane (1) (-phospha- (2), -arsena- (3)), 5-methyl-5-aza-1,3-dithiacyclohexane (4) (-phospha- (5), -arsena- (6)), and 5-methyl-5-aza-1,3-diselenacyclohexane (7) (-phospha- (8), -arsena- (9)). The MP2/6-311+G**//B3LYP/6-311+G** and B3LYP/6-311+G**//B3LYP/6-311+G** results revealed that the axial stereoisomers of compounds 1–9 are more stable than their equatorial stereoisomers. In this regard, the obtained results showed an egregious axial preference for compounds 1, 4, and 7. Importantly, the results showed that the energy differences between the axial and equatorial stereoisomers decrease from compounds 1 → 3, 4 → 6, and also, 7 → 9. The NBO analysis of donor–acceptor interactions revealed that the calculated DE for compounds 1–3 are –21.50, –7.84, and –4.38 kcal mol –1 , respectively. The decrease of the calculated DE values from compound 1 to compound 3 could reasonably explain the decrease of the energy differences between the axial and equatorial stereoisomers from compound 1 to compound 3. The correlation between the DE, dipole–dipole interactions, structural parameters, and conformational behaviors of compounds 1–9 has been investigated.
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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 | 0.001 |
| 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".