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Orthogonal Topochemical Reactions in a Single Crystal Mediated by Distinct Physical Stimuli
Anushka Balakrishnan1, Ravichandran Khazeber1,2, Kana M Sureshan1
1School of Chemistry, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India.
Angewandte Chemie (International Ed. in English)
|April 17, 2026
Summary
This study introduces a novel co-crystal exhibiting two distinct, stimulus-controlled chemical reactions. The material shows unprecedented orthogonal reactivity within a single crystal, paving the way for advanced materials.
Area of Science:
- Crystallography
- Organic Chemistry
- Materials Science
Background:
- Single crystals with multiple chemical transformations are rare.
- Achieving distinct transformations controlled by different stimuli within one crystal is unprecedented.
Purpose of the Study:
- To report a novel co-crystal with orthogonal reactivity.
- To demonstrate stimulus-dependent chemical transformations within a single crystal.
Main Methods:
- Co-crystal formation via hydrogen bonding and C-H interactions.
- Heat-driven topochemical click reaction of azide and alkyne groups.
- Light-driven topochemical [2+2] dimerization of olefin groups.
Main Results:
- Formation of an M:BPE co-crystal with complementary hydrogen bonding.
- Heat induces a single-crystal-to-single-crystal click reaction of M to a triazolyl-linked cyclic dimer.
- Photoirradiation induces [2+2] photodimerization of BPE to the rctt isomer.
Conclusions:
- The M:BPE co-crystal exhibits unprecedented orthogonal reactivity.
- Stimulus-dependent transformations are controlled independently by heat and light.
- This work presents the first example of orthogonal reactivity in a single crystal mediated by different external stimuli.
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