Mechanochemical transformation of planar polyarenes to curved fused-ring systems

The transformation of planar aromatic molecules into pi-extended non-planar structures is a challenging task and has not been realized by mechanochemistry before. Here we report that mechanochemical forces can successfully transform a planar polyarene into a curved geometry by creating new C-C bonds along the rim of the molecular structure. In doing so, mechanochemistry does not require inert conditions or organic solvents and provide better yields within shorter reaction times. This is illustrated in a 20-minute synthesis of corannulene, a fragment of fullerene C-60, in 66% yield through ball milling of planar tetrabromomethylfluoranthene precursor under ambient conditions. Traditional solution and gas-phase synthetic pathways do not compete with the practicality and efficiency offered by the mechanochemical synthesis, which now opens up a new reaction space for inducing curvature at a molecular level. The transformation of planar aromatic molecules into non-planar structures is a challenging task and has not been realized by mechanochemistry before. Here, the authors demonstrate that mechanochemical forces can transform a planar polyarene into a curved geometry by creating new C-C bonds along the rim of the molecular structure.

Automated summary

The study demonstrates that mechanochemical forces can transform planar polyarenes into curved geometries by creating new C-C bonds, offering better yields and shorter reaction times without the need for inert conditions or organic solvents. This opens up a new reaction space for inducing curvature at a molecular level.