Effect of Chirality on π-Stacking in Styrene and Maleimide Alternating Copolymers
Bibliographic record
Abstract
The effect of different chiral sequences in alternating copolymers of styrene and maleimide, poly(styrene-alt-dimethyl-N,N-propylamide) (SMI) was studied. The methods used for the SMI also applied to the general class of alternating copolymers of styrene and various maleimides. Only racemo-diisotactic polymers can associate into complexes because of the symmetrically distributed phenyl groups and maleimide monomers. This polymer is isotactic with respect to the chiral site of the styrene monomers (R, S) and isotactic with respect to the chirality of the maleimide [racemo (RR, SS)]. The maleimide, racemo (SS or RR) chirality, and the complementary S or R chirality in the styrene moiety form the repeating unit of racemo-diisotactic SMI. Structural deviations from the isotactic configurations induces an asymmetry in the distribution of styrene monomers and introduce bends in the polymer backbone, which prevent association through pi-stacking interactions. Semiempirical PM3 calculations on the SMI polymer have shown that this pi-stacking occurs when the polymers are separated by a distance about 10 A, and each pi-stacking pair formed from the styrene monomers has a stabilization energy of about 12 kJ/mol.
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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 | 0.001 |
| 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".