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Updated: Jul 16, 2026

Microwave-assisted Intramolecular Dehydrogenative Diels-Alder Reactions for the Synthesis of Functionalized Naphthalenes/Solvatochromic Dyes
Published on: April 1, 2013
Isomeric Dibenzodiindenophenanthrene Diradicaloids: Synthesis, Structures, Properties, and Efficient NIR Photothermal
Qing Jiang1, Xinyi Zheng1, Jianchao Li2
1College of Chemistry and Bioengineering, Hunan University of Science and Engineering, Yongzhou, China.
Structural isomerism in polycyclic hydrocarbons (PHs) creates novel organic diradicaloids with tunable electronic properties. These PHs exhibit unique redox behavior and serve as advanced near-infrared photothermal materials.
Area of Science:
- Organic Chemistry
- Materials Science
- Photochemistry
Background:
- Structural isomerism is key to tuning organic diradicaloid properties.
- Polycyclic hydrocarbons (PHs) are versatile molecular platforms.
Purpose of the Study:
- Synthesize and characterize isomeric open-shell PHs based on dicyclopenta[b,j]phenanthrene.
- Compare their diradical properties with anthracene-based isomers.
- Investigate their potential as near-infrared photothermal materials.
Main Methods:
- Synthesis and characterization of isomeric PHs (1-3).
- Experimental and theoretical studies of electronic structures and diradical properties.
- Electrochemical analysis for redox behavior.
- X-ray crystallography for structural confirmation.
- Near-infrared laser irradiation studies for photothermal properties.
Main Results:
- Isomeric PHs exhibit large diradical characters (y0 = 0.54-0.72).
- Small singlet-triplet energy gaps (ΔEST = -0.99 to -2.79 kcal/mol) and narrow HOMO-LUMO gaps (0.90-1.16 eV) were observed.
- Compounds show multistage reversible redox behavior, forming stable radical ions and dications.
- Excellent photothermal stability, conversion efficiency, and imaging performance under NIR irradiation.
Conclusions:
- Subtle structural isomerism significantly influences the electronic structure and properties of diradical PHs.
- These PHs represent a robust molecular platform for advanced near-infrared photothermal materials.
- The study provides deep insights into structure-property relationships in isomerism-engineered diradical PHs.
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