Directed Metalation-Cross Coupling Route to Ferroelectric Liquid Crystals with a Chiral Fluorenol Core: The Effect of Intermolecular Hydrogen Bonding on Polar Order
Bibliographic record
Abstract
The chiral fluorenol mesogen ( R )-2-(1-octyloxy)-7-((4-undecyloxybenzoyl)oxy)fluoren-9-ol (( R )- 3 ) was synthesized using a combined directed metalation-cross coupling strategy. The SmC* liquid crystal phase formed by the fluorenol mesogen is more stable and has a wider temperature range than that formed by the fluorenone presursor, which may be ascribed to intermolecular hydrogen bonding. The spontaneous polarization ( P S ) of ( R )- 3 at 10 K below the SmC*-I phase transition temperature is −10.7 nC/cm 2 . Molecular modeling based on the Boulder model suggests that the intrinsic conformational bias favoring one orientation of the fluorenol dipole moment along the polar axis of the SmC* phase is very subtle and implies that self-assembly via hydrogen bonding may play a role in enhancing polar order. Results from FT-IR spectroscopy, dilution with achiral SmC additives, and deuterium exchange experiments suggest that the spontaneous polarization is enhanced by the formation of fluorenol dimers via OH−O C hydrogen bonding. Such self-assembly should increase the rotational order about the long molecular axis and, therefore, the orientational bias of the fluorenol transverse dipole moment along the polar axis that gives rise to P S .
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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 | 0.000 | 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 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".