The right way to self-fuse bi- and terpyrenyls to afford graphenic cutouts

In this work, we subject bi- and terpyrenyls to selective fusion for formation of extended polycyclic aromatic hydrocarbons (PAHs). Connecting the pyrene units at 4-4'- or 1-4'-positions led to smooth formation of extended PAHs, achieved via cyclodehydrogenation. This is far more difficult if pyrene is coupled in the 1,1'-position.