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A Doubly Nitrogen-Bridged Chiral Spirobifluorene Dimeric Macrocycle: Synthesis, Properties, and Thermally Activated
Toru Amaya1, Haruka Mizukawa1, Tomoya Imai1
1Graduate School of Science, Nagoya City University, Mizuho-ku, Nagoya, Aichi467-8501, Japan.
Abstract:
A doubly nitrogen-bridged chiral spirobifluorene dimer with a rigid double-helical structure was synthesized, and its one-electron oxidized species was investigated as a mixed-valence system. Variable-temperature ESR measurements revealed thermally activated intramolecular electron exchange with a very small activation enthalpy (ΔH‡ = 1.25 kcal mol-1), despite limited electronic communication across the doubly spiro-linked redox units.
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