Towards understanding of magnetic interactions within a series of tetrathiafulvalene- conjugated- verdazyl diradical cation system: a density funtional theory study
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Bibliographic record
Abstract
The intramolecular magnetic exchange coupling constants (J) for a series of tetrathiafulvalene \n(TTF) and verdazyl diradical cations connected by a range of p conjugated linkers have been \ninvestigated by means of methodology based on unrestricted density functional theory. The \nmagnetic interaction between radicals is transmitted via p–electron conjugation for all considered \ncompounds. The calculation of J yields strong or medium ferromagnetic coupling interactions \n(in the range of 56 and 300 K) for diradical cations connected by linkers with an even number of \ncarbon atoms that are able to provide a spin polarization pathway, while antiferromagnetic \ncoupling is predicted when linkers with an odd number of carbon atoms are employed. The \ntopological analysis of spin density distributions have been used to reveal the effects of the spin \npolarization on both linkers and spin carriers. The absence of heteroatoms that impede the spin \npolarization pathway, and the existence of a unique spin polarization path instead of several \npossible competitive routes are factors which contribute to large positive J values favoring \nferromagnetic interactions between the two terminal p-radicals. The magnitude of J depends \nstrongly on the planarity of the molecular structure of the diradical cation since a more effective \norbital overlap between the two p-systems can be achieved. Hence, the dependence of J on the \ntorsion angle (y) of each spin carrier has been analyzed. In this respect, our findings show that \nthis geometrical distortion reduces largely the calculated J values for ferromagnetic couplings, \nleading to weak antiferromagnetic interactions for a torsion angle of 901
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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 | 0.001 | 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 | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| 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 it