Determination of outer-sphere dipolar time correlation functions from high-field NMR measurements. Example of a Gd3+ complex in a viscous solvent
Bibliographic record
Abstract
We consider a diamagnetic species carrying a nuclear spin and having a purely outer-sphere dynamics with respect to a Gd(3+) complex. The maximal structural and dynamic information attainable from the paramagnetic relaxation (rate) enhancement (PRE) of this nuclear spin due to the Gd(3+) electronic spin is the outer-sphere dipolar time correlation function (OS-DTCF) of the relative position of these spins. We show how to determine this OS-DTCF by a model-free analysis of high-field PRE measurements, which accounts for the relative diffusion coefficient of the spin carrying species derived from pulsed-gradient spin-echo experiments. The method rests on the spectral characterization of the OS-DTCF through a PRE property, the "star" relaxivity, which can be measured over an unexpectedly large frequency range by combining multiple field and temperature NMR experiments. It is illustrated in the case of the (1)H spins on the three diamagnetic probes tert-butanol CHD(2)(CD(3))(2)COD and glycerol (CD(2)OD)(2)CHOD and CHDOD-CDOD-CD(2)OD interacting with Gddtpa(2-) (dtpa(5-)=diethylen triamin pentaacetate) in a viscous glycerol-d8/D(2)O solvent. The general usefulness of the OS-DTCF for the description of the liquid state and electronic spin relaxation is discussed.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".