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Record W2066695434 · doi:10.1021/jp020378e

Hyperfine and Host−Guest Interactions of the Mu-Cyclohexadienyl Radical in NaY Zeolite

2002· article· en· W2066695434 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueThe Journal of Physical Chemistry B · 2002
Typearticle
Languageen
FieldEngineering
TopicMuon and positron interactions and applications
Canadian institutionsUniversity of British ColumbiaTRIUMF
Fundersnot available
KeywordsMuoniumChemistryHyperfine structureZeoliteMuon spin spectroscopyElectron paramagnetic resonanceMoleculeAdsorptionRadical ionResonance (particle physics)BenzeneCrystallographyRadicalMuonPhotochemistryPhysical chemistryAtomic physicsIonNuclear magnetic resonanceOrganic chemistry

Abstract

fetched live from OpenAlex

The adsorption and dynamical behavior of the muonated cyclohexadienyl radical (C 6 H 6 Mu) in NaY zeolite, formed by muonium (Mu) addition on adsorbed benzene, was investigated by the muon spin resonance (μSR) technique, primarily at loadings of 2−3 C 6 H 6 molecules per supercage of NaY. The dynamics of this radical are expected to be the same as its isotopic analogue, C 6 H 7, for which there are no similar data available. Both TF-μSR and ALC-μSR spectra were recorded, with the most detailed information provided by the positions and line widths of the avoided level crossing resonances. In concert with 2 H NMR, neutron diffraction and molecular dynamics studies of the parent benzene molecule, as well as current theoretical calculations, the dominant adsorption site for the C 6 H 6 Mu radical is believed to be the S II Na cation, within a supercage, which gives rise to three observed ALC lines, corresponding to two different orientations for the muon (proton) of the CHMu methylene group: pointing toward (endo) and away (exo) from the Na cation. The cation interaction gives rise to unprecedentedly large (≈20%) shifts in hyperfine coupling constants, indicative of a strong bond formed with the π electrons of the C 6 H 6 Mu radical. An additional but weaker resonance line is also seen, which is interpreted as being due to adsorption at the window sites between supercages. The ALC lines associated with the C 6 H 6 Mu radical bound to both the Na cation and window sites are all broad, ≈1 kG, change little with temperature and exhibit mainly static line shapes over the whole temperature range studied, from 3 to 322 K. This indicates a much stronger host−guest interaction for C 6 H 6 Mu, particularly with the Na cation, than is known for benzene, to the extent that this site acts as an effective trap for the free radical, over the critical μSR time scale of 50 ns.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.173
Threshold uncertainty score0.149

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.007
GPT teacher head0.213
Teacher spread0.206 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it