Inner-Bond Cleavage in Nanographenes: A Constructive Destruction Strategy for Facile Access to Molecules with Multiple Figure-Eight Structures

The elegant architectures of nonplanar π-systems, such as fullerene and corannulene, exhibit distinctive functionalities that have played a significant role in advancing science and technology. The current approach to synthesizing nonplanar π-systems heavily relies on the stepwise formation of bonds between their constituent fragments, which is known as the bottom-up approach. The limited number of synthetic pathways to nonplanar π-systems inevitably results in impractical molecular frameworks. Herein, we demonstrate that a constructive destruction approach, based on the oxidative cleavage of internal double bonds of dibenzo[g,p]chrysene that immediately produces eightphenone: the first readily available figure-eight molecule. Eightphenone adopts a D2-symmetric structure with excellent configurational stability and is a highly efficient emitter of circularly polarized phosphorescence. The oxidative cleavage of internal double bonds is also applicable to larger nanographene molecules, resulting in unprecedented structures with multiple figure-eight units. This study introduces the concept of constructive destruction as an alternative to conventional bottom-up approaches, paving the way for the design of new materials.