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Sample Preparation and Experimental Design for In Situ Multi-Beam Transmission Electron Microscopy Irradiation Experiments
Published on: June 27, 2022
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Single-Crystal-to-Single-Crystal Radical-Ion Chain Reactions under the Electron Microscope: A Chemical Design to
Krzysztof A Konieczny1, Rishika Rai1, José A Rodriguez1
1Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States.
Journal of the American Chemical Society
|November 19, 2025
Summary
Templated crystals facilitate electron beam-induced single-crystal-to-single-crystal reactions, enabling structural analysis via 3D electron diffraction (3D ED). This method mitigates crystal damage, allowing detailed observation of reaction pathways.
Area of Science:
- Crystallography
- Materials Science
- Electron Microscopy
Background:
- Single-crystal-to-single-crystal (SC-SC) reactions are crucial for materials transformations.
- Electron beam irradiation in electron microscopy can induce chemical changes, potentially damaging crystal lattices.
- Supramolecular templating offers a strategy to control crystal reactivity and stability.
Purpose of the Study:
- To investigate the use of electron beam-induced SC-SC reactions for structural elucidation using 3D electron diffraction (3D ED).
- To compare the reaction behavior and crystal stability in templated versus nontemplated crystalline materials.
- To understand the role of ionization events in initiating and propagating these reactions.
Main Methods:
- Utilized microcrystals of rctt-tetrakis(4-pyridyl)cyclobutane (bpeD) complexed with 2,4-dichlororesorcinol (dcr) or 2,4,6-trichlorophenol (tcp) for templated SC-SC reactions.
- Employed 3D electron diffraction (3D ED) for structural determination at various reaction stages.
- Compared results with nontemplated bpeD complexes and pure trans-4,4'-bipyridylethene (bpe) crystals.
Main Results:
- Templated bpeD·dcr and bpeD·tcp crystals underwent smooth SC-SC cyclobutane splitting reactions to form bpe complexes.
- Electron beam ionization initiated reactions, propagated by electron transfer, with significantly mitigated beam damage.
- Nontemplated bpeD·icCA and pure bpe crystals showed sluggish, non-SC-SC reactions and rapid diffraction decay.
Conclusions:
- Supramolecular templating enables controlled SC-SC reactions under electron beam irradiation, facilitating structural studies.
- Ionization-induced chemical changes are key to reaction initiation and propagation, but templating minimizes detrimental crystal damage.
- The findings highlight the importance of crystal structure and templating in preserving sample integrity during electron microscopy analysis.
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