Characterization of Bodipy Dimers Formed in a Molecularly Confined Environment
Bibliographic record
Abstract
Recently, Johansson and co-workers provided the first direct evidence for the existence of nonfluorescent bodipy (4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene) H dimers in double-labeled proteins and fluorescent J dimers in labeled lipid vesicles (Bergstrom, F.; et al. J. Am. Chem. Soc. 2002, 124, 196), allowing for the calculation of many of the properties of the dimers. Herein, we report on the use of molecular confinement within a sodium silicate derived glass to provide a highly reproducible system wherein nonfluorescent bodipy H dimers can be formed from the free probe essentially quantitatively without any interference from higher-order aggregates or fluorescent J dimers. The formation of the H dimer followed an unexpected first order kinetic process. On the basis of analysis of the fluorescence anisotropy of the entrapped monomer, it was concluded that the H-dimer formation was promoted by adsorption of monomers onto the silica surface (rate limiting step), followed by rapid dimerization. Using exciton coupling theory, it was determined that the H dimer consisted of two strongly coupled monomers that were stacked in a parallel orientation with a distance of 7.6 Å between the monomer units. The transition dipole moment of the monomer was determined to be 26.6 × 10 -30 C m (8.1 D), the emission quantum yield of the H dimer was found to be close to zero, and the Förster distance for energy transfer between the monomer and H dimer was calculated to be 56 ± 2 Å. All of these values are in excellent agreement with those determined by Johansson et al.
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How this classification was reachedexpand
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) | 0.000 | 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 teacher head, 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".