Atomically precise bottom-up synthesis of π-extended [5] triangulene

Chemists have predicted zigzag-edged triangular graphene molecules (ZTGMs) to host ferromagnetically coupled edge states, with net spin scaling with the molecular size. Such molecules can afford large spin tunability, which is crucial to engineer next-generation molecular spintronics. However, the scalable synthesis of large ZTGMs and the direct observation of their edge states are a long-standing challenge due to the high chemical instability of the molecule.