Coordination Complexes of Decamethylytterbocene with 4,4'-Disubstituted Bipyridines: An \nExperimental Study of Spin Coupling in Lanthanide Complexes
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.
Bibliographic record
Abstract
The paramagnetic 1:1 coordination complexes of (C5Me5)2Yb with a series of 4,4'-disubstituted bipyridines, bipy-X, where X is Me, tert-Bu, OMe, Ph, CO2Me, and CO2Et have been prepared. All of the complexes are paramagnetic and the values of the magnetic susceptibility as a function of temperature show that these values are less than expected for the cation, [(C5Me5)2Yb(III)(bipy-X)]+, which have been isolated as the cation-anion ion-pairs [(C5Me5)2Yb(III)(bipy-X)]+[(C5Me5)2YbI2]f fnfn where X is CO2Et, OMe and Me. The 1H NMR chemical shifts (293 K) for the methine resonances located at the 6,6' site in the bipy-X ring show a linear relationship with the values of chiT (300 K) for the neutral complexes which illustrates that the molecular behavior does not depend upon the phase with one exception, viz., (C5Me5)2Yb(bipy-Me). Single crystals of the 4,4'-dimethylbipyridine complex undergo an irreversible, abrupt first order phase change at 228 K that shatters the single crystals. The magnetic susceptibility, represented in a delta vs. T plot, on this complex, in polycrystalline form undergoes reversible abrupt changes in the temperature regime 205 - 212 K, which is suggested to be due to the way the individual molec ular units pack in the unit cell. A qualitative model is proposed that accounts for the sub-normal magnetic moments in these ytterbocene-bipyridine complexes.
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 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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.005 |
| Open science | 0.001 | 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 it