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Updated: May 11, 2026

Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
Evaluation of triplet aromaticity by the isomerization stabilization energy
Jun Zhu1, Ke An, Paul von Ragué Schleyer
1State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, China, Department of Chemistry, University of Georgia , Athens, Georgia 30602-2525, United States, and Laboratory of Chemical Genomics, Shenzhen Graduate School of Peking University , Shenzhen 518055, China.
Abstract:
The many manifestations of aromaticity have long fascinated both experimentalists and theoreticians. Due to their degenerate half-filled MOs, triplet [n]annulenes with 4n π-electrons are also aromatic, but the degree of their stabilization has been difficult to quantify. The isomerization stabilization energy (ISE) method has been applied to evaluate the triplet aromaticity. The reliability of this approach is indicated by the strong correlation of the ISE results with NICS(1)zz, a magnetic indicator of triplet state aromaticity.
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