Prediction of Subcooled Vapor Pressures of Nonpolar Organic Compounds Using a One-Parameter QSPR
Bibliographic record
Abstract
A previously derived empirical linear relationship between the average polarizability of chlorinated aromatic and aliphatic compounds, α m, as calculated using density functional theory methods, and their subcooled liquid vapor pressure, log p L, is tested here for its capability to predict the 25 °C subcooled vapor pressures of a diverse set of nonpolar organic compounds, including 12 brominated benzenes, 13 aromatic hydrocarbons, 10 chlorinated toluenes, 3 hexachlorocyclohexanes, and p, p ‘-DDT. A comparison with experimental data shows generally excellent agreement over a 10-order-of-magnitude range in p L, with an average error of less than 0.5 log unit. Experimental vapor pressure values were taken from the literature or, in the case of the chlorinated toluenes, were determined using gas chromatographic retention times. Remarkably large differences in the experimental octanol−air partition coefficients for the isomers of the hexachlorocyclohexanes were found to correspond to similarly large differences in the out-of-plane polarizabilities of these substances. This work suggests that a single theoretically derived parameter is sufficient to estimate within 1 order of magnitude the volatility of a wide variety of organic compounds whose primary interactions are dispersive in nature. This includes halogenated and nonhalogenated, aromatic, aliphatic and alicyclic, and planar and nonplanar organic substances.
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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 | 0.001 | 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".