Effects of External Electric Field and Self-Aggregations on Conformational Transition and Optical Properties of Azobenzene-Based D-π-A Type Chromophore in THF Solution
Bibliographic record
Abstract
The influence of environments (THF solvents and electric field) and molecular self-aggregations on the structure and optical properties of 4-(4-hydroxyphenylazo)nitrobenzene has been investigated by molecular dynamics (MD) simulations and quantum chemical calculations. Long-range electrostatic effects and the hydrogen bond interactions between the solute and the THF solvent molecules lead to the augments of nonlinear optical (NLO) response by about two times from the gas phase to THF solution, accompanied by considerable red-shift of more than 40 nm in the maximum absorption wavelengths of the ground (S<sub>0</sub>) and low-lying excited states (S<sub>1</sub>, S<sub>2</sub>, and S<sub>3</sub>). The solvated chromophore reorients quickly (within 300 ps) under external electric field of 1.0 V/nm, even when the direction of the applied electric field is antiparallel to the dipole moment of the solute. Nonequilibrium MD simulations demonstrate that the light-induced <i>cis</i>–<i>trans</i> isomerization in THF solution and external electric field need longer relaxation time (about 1.0 ps) than that in gas phase (about 500 fs). The dipole–dipole interactions and intermolecular hydrogen bonds facilitate the self-aggregations of solute molecules in solution. The V-shaped dimer exhibits higher hyperpolarizability value by about 1.2 times of the monomer, whereas the antiparallel alignment leads to a cancellation of dipole moment and hence dramatic decrease in hyperpolarizability (one-third of the monomer). However, the Boltzmann-weighted contribution to hyperpolarizability from these two aggregations (with 82% V-shaped and 18% antiparallel) is close to that of the monomer. Orientations of D-π-A dipoles in various environments and molecular aggregations are important to modulate the optical properties of materials.
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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) | 0.000 | 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 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".