Evidence map›Paper›PMID 41193716›Full record

ArticleCommunications chemistry2025

Polytypes and planar defects revealed in the purine base xanthine using multi-dimensional electron diffraction.

Helen W Leung, Royston C B Copley, Giulio I Lampronti, Sarah J Day, Lucy K Saunders, Duncan N Johnstone, Paul A Midgley

Abstract read
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Article in Communications chemistry, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing 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

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3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

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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

7 authors.

Helen W LeungDepartment of Materials Science and Metallurgy, University of Cambridge, Cambridge, United Kingdom. hl585@cam.ac.uk.ORCID http://orcid.org/0000-0002-5434-8673
Royston C B CopleyGSK R&D, Stevenage, United Kingdom.ORCID http://orcid.org/0000-0002-8662-3895
Giulio I LamprontiDepartment of Materials Science and Metallurgy, University of Cambridge, Cambridge, United Kingdom.ORCID http://orcid.org/0000-0002-1430-3446
Sarah J DayDiamond Light Source Ltd, Beamline I11, Harwell Campus, Didcot, United Kingdom.
Lucy K SaundersDiamond Light Source Ltd, Beamline I11, Harwell Campus, Didcot, United Kingdom.ORCID http://orcid.org/0000-0001-5689-8129
Duncan N JohnstoneGSK R&D, Upper Providence, USA.
Paul A MidgleyDepartment of Materials Science and Metallurgy, University of Cambridge, Cambridge, United Kingdom. pam33@cam.ac.uk.ORCID http://orcid.org/0000-0002-6817-458X

Funding

Diamond Light Source CY34800RCUK | Engineering and Physical Sciences Research Council (EPSRC) EP/W522120/1 and EP/R008779/1
6 · The paper itself

Abstract

Layered crystal structures are commonly found across organic and inorganic material systems. When in-plane atomic arrangement remains (nearly) identical, a stacking variation of these layers may result in twinning, planar disorder, or polytypes, a form of polymorphism derived from altering stacking sequences. In this work, we use multi-dimensional electron diffraction (ED) modalities to explore the microstructure of xanthine, an archetypal purine base with a layered crystal structure. Firstly, we identify and characterise the twin operator relating domains of Form I xanthine. We then solve the structure of a new xanthine polymorph, revealing that it is a polytype of Form I. Finally, interfaces between twin and polytype domains are visualised, whilst streaking in the diffraction patterns reveals the presence of planar disorder. Given these observations in the xanthine system, this work suggests that disorder on the nanoscale may be a commonly occurring phenomenon in layered organic molecular crystals.

Identifiers

PMID41193716
PMCPMC12589599

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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.