Quantifying the Likelihood of Structural Models through a Dynamically Enhanced Powder X‐Ray Diffraction Protocol

• Published in: Angewandte Chemie International Edition 2021-04, Vol.60 (16), p.8913-8922
• Main Authors: Borgmans, Sander, Rogge, Sven M. J., De Vos, Juul S., Stevens, Christian V., Van Der Voort, Pascal, Van Speybroeck, Veronique
• Format: Article
• Language: English
• Subjects: Atomic structure; covalent organic frameworks; Crystal structure; Diffraction patterns; Functional materials; materials characterization; operando modeling; Single crystals; Structural analysis; Structural models; structure prediction; Structure-function relationships; Topology; X-ray diffraction
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202017153

Structurally characterizing new materials is tremendously challenging, especially when single crystal structures are hardly available which is often the case for covalent organic frameworks. Yet, knowledge of the atomic structure is key to establish structure‐function relations and enable functional material design. Herein, a new protocol is proposed to unambiguously predict the structure of poorly crystalline materials through a likelihood ordering based on the X‐ray diffraction (XRD) pattern. Key of the procedure is the broad set of structures generated from a limited number of building blocks and topologies, which is submitted to operando structural characterization. The dynamic averaging in the latter accounts for the operando conditions and inherent temporal character of experimental measurements, yielding unparalleled agreement with experimental powder XRD patterns. The proposed concept can hence unquestionably identify the structure of experimentally synthesized materials, a crucial step to design next generation functional materials. Structurally characterizing new and poorly crystalline materials such as covalent organic frameworks is highly challenging. The dynamic protocol of this work overcomes this challenge through a systematic likelihood ordering based on intuitive heuristics and X‐ray diffraction patterns. It succeeds in unambiguously identifying a material's atomic‐level structure, accounting for the operando conditions and inherent temporal character of experiments.