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EPR Active Supramolecular Gel With Network Fabrication: Selective H2O2 Induced EPR Enhancement From a Soft Gel
Mohit Kulshrestha1, Reena Kyarikwal1, Kalyan K Sadhu1
1Department of Chemistry, Indian Institution of Technology Roorkee, Roorkee, Uttarakhand, India.
Chemistry, an Asian Journal
|February 27, 2026
Summary
This study stabilizes short-lived chromenopyridine radicals (CP•) in rigid supramolecular gels. These gels demonstrate stable Electron Paramagnetic Resonance (EPR) activity, even after hydrogen peroxide treatment, showing potential for radical stabilization.
Area of Science:
- Supramolecular Chemistry
- Materials Science
- Radical Chemistry
Background:
- Supramolecular gels offer a unique matrix for stabilizing transient chemical species.
- Short-lived radicals, like flavin mononucleotide hydride, pose challenges for study due to their instability.
- Stabilizing synthesized radicals in supramolecular networks is crucial for understanding their properties.
Purpose of the Study:
- To stabilize the synthesized chromenopyridine radical (CP•) within a supramolecular gel network.
- To investigate the rigidity aspects of Electron Paramagnetic Resonance (EPR) active multicomponent supramolecular gels.
- To explore the formation and stability of CP• in gels derived from dicyanomethylchromenopyridine (DCP•) and aromatic amines.
Main Methods:
- Formation of supramolecular gels using DCP• and various aromatic di-/tri-amines in DMSO/water mixtures.
- Characterization of gel rheological properties and morphologies.
- Evaluation of EPR activity and stability of the gels, including post-hydrogen peroxide (H2O2) treatment.
- Mass spectrometry to detect CP-OH adducts for radical formation validation.
Main Results:
- Supramolecular gels were successfully formed, with DCP• converting to CP• during gelation.
- Gel properties (rheology, morphology) were tunable based on amine structure and solvent composition.
- The EPR activity of the rigid gels remained stable after H2O2 treatment.
- A specific soft gel showed enhanced EPR intensity post-H2O2 treatment due to DCPC• formation, validated by CP-OH adducts.
Conclusions:
- Rigid supramolecular gels provide a stable environment for the chromenopyridine radical (CP•).
- The system demonstrates potential for stabilizing and studying short-lived radical species.
- The study highlights the influence of gel composition on radical stability and EPR response.
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