Evidence map›Paper›PMID 41406235›Full record

ArticleScience advances2025

A hydroxyl group dictates handedness, pitch, and mechanics in a crystalline covalent helical polymer.

Ravichandran Khazeber, Divina Xavier, Kana M Sureshan

Abstract read
In one paragraph

Article in Science advances, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Ravichandran KhazeberSchool of Chemistry, IISER Thiruvananthapuram, Kerala, 695551 (India).ORCID 0000-0003-2143-7626
Divina XavierSchool of Chemistry, IISER Thiruvananthapuram, Kerala, 695551 (India).ORCID 0009-0000-4966-0999
Kana M SureshanSchool of Chemistry, IISER Thiruvananthapuram, Kerala, 695551 (India).ORCID 0000-0002-4005-3655

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Helical polymers are fascinating materials, yet retaining their helicity in the solid state remains a key challenge for practical applications. Here, we present a regiospecific topochemical azide-alkyne cycloaddition for synthesizing crystalline covalent helical polymers via a single-crystal-to-single-crystal transformation. Building on our prior glycine-proline-based systems, we investigated the effect of subtle modification: introducing a hydroxyl group to the proline unit. This minor change induced a helicity reversal (left- to right-handed) and a substantial reduction in pitch (8.9 to 4.9 Å). Single-crystal x-ray diffraction revealed that this profound reordering is driven by intra- and intermolecular hydrogen bonds (C─H⋯O and O─H⋯N), acting as supramolecular bridges between helices, enabling denser packing. Consequently, the glycine-hydroxyproline-based polymer exhibited markedly enhanced mechanics, with a Young's modulus of 18.57 ± 2.01 GPa and hardness of 1.09 ± 0.13 GPa, surpassing natural collagen. This study provides insights into controlling polymer topology and mechanics through subtle modifications, establishing a powerful paradigm for the design of next-generation helical materials with tailored functionalities.

Identifiers

PMID41406235
PMCPMC12710711

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.