Publications by authors named "Ryuoh Ito"

We prepared a new overcrowded tristricyclic aromatic ene (TAE) and investigated its external stimuli-responsive behavior for the switching between a closed-shell folded form and an open-shell twisted form. Upon photoirradiation, the folded form transforms into the biradical twisted form, whereas by keeping the twisted form in the dark, the reverse reaction gradually occurs at room temperature. This switchable conformational change is analyzed by means of UV-vis and electron spin resonance spectroscopies, cyclic voltammetry, density functional theory calculations, and kinetic studies.

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Anthracene-attached tricyclic aromatic hydrocarbon radicals having different central polygons, Ant-5, Ant-6, and Ant-7, were synthesized to evaluate the role of an anthracene substituent group in the stability and reactivity of tricyclic aromatic hydrocarbon radicals. The bulky anthryl group effectively protects a carbon atom with high spin density, resulting in high persistence of the radicals. On the other hand, the combination of the anthryl group and the tricyclic aromatic scaffold makes the molecular structure drastically change from a twisted form to a folded form and an unpaired electron moves into the anthryl moiety, eventually affording a tail-to-tail σ-dimer.

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