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Record W1968093466 · doi:10.1021/jp021679r

High-Pressure <sup>129</sup>Xe NMR Study of Xenon Confined in the Nanochannels of Solid (±)-[Co(en)<sub>3</sub>]Cl<sub>3</sub>

2002· article· en· W1968093466 on OpenAlex
Takahiro Ueda, Taro Eguchi, Nobuo Nakamura, Roderick E. Wasylishen

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
FieldPhysics and Astronomy
TopicAtomic and Subatomic Physics Research
Canadian institutionsUniversity of Alberta
Fundersnot available
KeywordsXenonChemistryIsotopes of xenonIsotropyAmbient pressureAnalytical Chemistry (journal)Nuclear magnetic resonanceCrystallographyThermodynamicsPhysicsOrganic chemistry

Abstract

fetched live from OpenAlex

High-pressure 129 Xe NMR measurements were carried out on dehydrated (±)-[Co(en) 3 ]Cl 3 to investigate the pore size as well as the local structure about the confined xenon atoms. At xenon gas pressures of 0.3 MPa, the xenon chemical shift was orientation dependent, exhibiting an axially symmetric powder pattern with δ 11 = 280 ppm and δ 22 = δ 33 = 180 ppm. Proton to 129 Xe cross-polarization (CP) experiments selectively enhanced the portion of the powder pattern corresponding to δ 22 = δ 33 = δ ⊥, confirming that the unique component of the chemical shift tensor, δ 11 = δ ∥, lies along the pore axis. The isotropic chemical shift δ iso at the zero pressure limit was found to be 212 ppm, and suggested a pore diameter of approximately 0.47 nm. This agrees well with the diameter of 0.44 nm estimated from the crystal structure. On increasing the pressure to 6.5 MPa, δ ⊥ increased from 180 to 220 ppm, whereas δ ∥ was found to be almost independent of pressure. The increase in δ ⊥ with pressure is attributed to Xe−Xe interactions. The paramagnetic shift in the xenon chemical tensor component perpendicular to the nanochannels with increasing pressure is in accord with the recent theoretical predictions of Jameson and de Dios ( J. Chem. Phys. 2002, 116, 3805) and Jameson ( J. Chem. Phys. 2002, 116, 8912).

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)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
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 score0.014
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0000.001
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 head0.014
GPT teacher head0.266
Teacher spread0.252 · 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