Observation of Quinoxalinyl Radical Produced by Muonium Addition to 1,2‐Diisocyanobenzene
Bibliographic record
Abstract
Radical isocyanide (isonitrile) insertion reactions have advanced considerably, yet the nature of the underlying paramagnetic intermediates remains poorly understood. We previously studied the isocyanide insertion of muonium (Mu), a light isotope of hydrogen, into 2-isocyano-1,1'-biphenyls by transverse field muon spin rotation (TF-µSR) spectroscopy and characterized the resulting radical, which was identified as an imidoyl radical. The cyclized product was not observed on the microsecond timescale. To gain deeper insight, we now report TF-µSR spectra of 1,2-diisocyano-3,4,5,6-tetramethylbenzene in both THF solution and the crystalline state. A single muoniated radical species was observed, displaying an unusually small muon hyperfine coupling constant (hfc). Guided by density functional theory (DFT) calculations, we identified this species as a quinoxalinyl radical, formed via intramolecular cyclization of the imidoyl intermediate. This observation implies that the imidoyl radical survives only on the nanosecond timescale before cyclization.
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 | 0.000 |
| 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".