Beyond PXRD Pattern Matching: Toward Rigorous Structure Determination in Covalent Organic Frameworks
1Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee, USA.
Angewandte Chemie (International Ed. in English)
|August 5, 2026
Summary
Overreliance on powder X-ray diffraction (PXRD) for covalent organic framework (COF) structures leads to errors. More rigorous methods and transparent data are crucial for accurate COF structure determination and reliable results.
Area of Science:
- Materials Science
- Crystallography
- Chemistry
Background:
- Qualitative powder X-ray diffraction (PXRD) pattern matching is widely used for determining covalent organic framework (COF) structures.
- This approach has led to systematic overinterpretation of COF structures, obscuring structure-property relationships and leading to misleading mechanistic conclusions.
Purpose of the Study:
- To critically examine the weaknesses in current practices for COF structure determination.
- To highlight the mismatches between proposed structural models and supporting characterization data.
- To advocate for more rigorous, evidence-based approaches for reliable COF structure determination.
Main Methods:
- Analysis of common weaknesses in current COF structure determination practices.
- Review of representative case studies illustrating inconsistencies between structural models and characterization data.
- Emphasis on complementary characterization techniques for robust structure determination.
Main Results:
- Identified systematic overinterpretation of COF structures due to over-reliance on qualitative PXRD.
- Demonstrated how inconsistencies arise and impact mechanistic conclusions and reported performance.
- Highlighted the need for complementary techniques beyond PXRD for accurate structural validation.
Conclusions:
- More rigorous, evidence-based approaches using complementary characterization techniques are essential for reliable COF structure determination.
- Transparent data reporting and deposition are critical for assessing the validity of structural claims in COFs.
- A practical checklist is proposed to aid authors, reviewers, and editors in evaluating structural claims.
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