Dibenzoannulated 3,5,5",5"-Tetra(t-butyl)-p-terphenoquinone. A Reversible, PhotochemicalThermal Switching System Involving Restricted Conformational Change

The title compound, a new terphenoquinone derivative, shows a dynamic redox behavior upon cyclic voltammetry and a reversible, photochemical-thermal isomerization between the quinone and diradical forms, both phenomena involving restricted conformational change.