Room-Temperature and Solution-State Observation of the Mixed-Valence Cation Radical Dimer of Tetrathiafulvalene, [(TTF)2] within a Self-Assembled Cage.

This article focuses on the properties of mixed-valence cation radical dimer of tetrathiafulvalene (TTF) within a self-assembled cage. TTF is a strong electron donor and apt to generate the stable cation radical TTF upon oxidation. Electrochemical studies showed the unique behavior of accommodated TTF molecules. A striking feature was that the former oxidation wave around 200 mV could be resolved into two waves at the peak potentials of 152 and 304 mV. Through the accommodation in a self-assembled cage, the generation and observation of a mixed-valence dimer was made possible. It is particularly interesting that a weak dimeric species, which typically cannot be generated unless covalently linked, is observed in cage.