Interplay of Ionic, Hydrogen-Bonding, and Polar Interactions in Liquid Crystalline Complexes of a Pyridylpyridinium Polyamphiphile with (Azo)phenol-Functionalized Molecules
Bibliographic record
Abstract
Most supramolecular side-chain polymers investigated to date are based on a single type of noncovalent link and involve systems that do not test its selectivity in the presence of other potentially interfering interactions. In this paper, we study the selectivity of hydrogen-bond complexation in the presence of both ionic moieties and highly polar groups and evaluate the effect of these potentially interacting functions on the self-assembly and thermotropic behavior of the intended side-chain liquid crystal (LC) polymer complexes. To this end, the weakly mesomorphic polyamphiphile, poly(ω-pyridylpyridinium dodecyl methacrylate) bromide ( P12PP ), where the side chains are terminated by a hydrogen-bond acceptor in close proximity to an ion pair, is mixed in equimolar proportion with a series of phenol-functionalized mesogenic complexants ( X ), some of which have highly polar tails, while others have chiral tails and most contain an azo moiety for potential optical responsiveness. It is found that, in all cases, hydrogen-bond complexation is successful and essentially complete, leading to supramolecular homopolymeric complexes P( X ) with well-defined thermotropic LC characteristics. These complexes, which are partially crystalline initially, have above-ambient glass transitions and smectic LC mesophases that are monotropic, enantiotropic or effectively enantiotropic, depending on the molecular characteristics of X . The presence of a polar tail hampers recrystallization after melting, with a cyano tail suppressing it completely and also strongly retarding the development of the LC mesophase from the isotropic phase. This might be related to enhanced electrostatic interactions and increased viscosity in the melt. The mesophase periodicity of P12PP is unchanged by complexants with a flexible alkyl tail, suggesting that they can adapt to the packing structure of P12PP (previously reported to be partial bilayer smectic A-like), whereas more rigid albeit shorter complexants lead to a periodicity increase (indicative of an effective single-layer smectic A mesophase). Possible molecular packing models are presented and discussed.
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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".