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Updated: Jan 5, 2026

Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
Photo- and Thermal Interconversion of Multiconfigurational Strained Hydrocarbons Exhibiting Completely Switchable
Yusuke Ishigaki1, Yuki Hayashi1, Takanori Suzuki1
1Department of Chemistry, Faculty of Science , Hokkaido University , Sapporo 060-0810 , Japan.
Abstract:
Highly strained hydrocarbons with two di/tribenzocycloheptatriene units were designed as electrochromic overcrowded ethylenes that undergo reversible interconversion with stable dicationic dyes. Due to severe steric repulsion, two configurational isomers (anti,anti-folded and syn,anti-folded forms) were isolated as stable entities. Photo- and thermal interconversion of these isomers proceeded cleanly: one-way photoisomerization occurred from anti,anti- to syn,anti-form and one-way thermal isomerization was observed from syn,anti- to anti,anti-form. Even though both isomers undergo two-electron oxidation into the same twisted dications, quite different oxidation potentials enable completely selective oxidation of syn,anti-isomers. Thus, the present multiconfigurational strained hydrocarbons are capable of switching of activation/deactivation of their electrochromic properties by light/heat.
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