Generation and Reactivity of Simple Chloro(aryl)carbenes within the Cavities of Nonacidic Zeolites
Bibliographic record
Abstract
A number of para-substituted chloro(aryl)carbenes are generated within the cavities of a series of dry alkali metal cation-exchanged zeolites (LiY, NaY, KY, RbY, and CsY) upon laser flash photolysis of the corresponding diazirine precursor. The absolute reactivity of the chloro(aryl)carbene is found to be strongly dependent on both the nature of the electron-donating and -withdrawing properties of the aryl substituent and the nature of the zeolite charge-balancing cations. The results strongly suggest that two opposing mechanisms for capture of the carbene can occur depending on whether the zeolite framework behaves as a nucleophilic reagent or an electrophilic reagent in its reaction with the carbene center. Hammett relationships for the decay of the carbene as a function of aryl substituent and zeolite counterion versus the sigma+ substituent parameter support a change in mechanism as the carbene center toggles between being electron poor and electron rich. For the electron-poor chloro(4-nitrophenyl)carbene, a framework adduct is proposed upon reaction of the nucleophilic [Si-O-Al]- bridge with the carbene center, and for the electron-rich chloro(4-methoxyphenyl)carbene, an adduct with the tight Li+ cation is proposed.
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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".