Two-Photon Absorption of BODIPY, BIDIPY, GADIPY, and SBDIPY
Bibliographic record
Abstract
Substituted boron-dipyrromethene compounds (BODIPYs) have gained significant attention due to their tunable photophysical properties, including two-photon absorption (2PA), a nonlinear optical process where two photons are absorbed simultaneously. The tuning of BODIPY's photophysical properties has recently led to the synthesis of pnictogen-containing derivatives, such as SBDIPY and BIDIPY, where boron is replaced by antimony (Sb) or bismuth (Bi), respectively, as well as other analogues like GADIPY, which contain gallium (Ga). This study presents a computational investigation into their 2PA properties, exploring the impact of various substitutions across these systems. The 2PA cross-sections (σ2PA), electronic excitation energies (ΔE), and dipole moments (µ00, µ11, µ01, Δµ) were computed for 18 DIPY chromophores in the gas-phase with time-dependent density-functional theory (TD-DFT) using several functionals (CAM-B3LYP, ωB97X, M06-2X, M11, and MN15), and then compared to RI-CC2 results. The computed mean absolute errors were small, with the MN15, CAM-B3LYP, and M06-2X functionals being among the best-performing for the properties analyzed. In general, for the parent (unsubstituted) compounds, replacing the core atom in DIPY chromophores results in negligible changes to their σ2PA. However, extending the conjugation through the addition of phenyl substituents significantly increases σ2PA values, and the nature of the core atom impacts the magnitude of this enhancement.
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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 | 0.000 |
| 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".