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

• DOI: 10.1126/sciadv.aav7717
• Publication Date: 2019-07-26T23:15:11Z
• Authors: Jie Su; Mykola Telychko; Pan Hu; Gennevieve Macam; Pingo Mutombo; Hejian Zhang; Yang Bao; Fang Cheng; Zhi-Quan Huang; Zhizhan Qiu; Sherman J. R. Tan; Hsin Lin; Pavel Jelínek; Feng-Chuan Chuang; Jishan Wu; Jiong Lu
• Keywords: Zigzag

The zigzag-edged triangular graphene molecules (ZTGMs) have been predicted to host ferromagnetically coupled edge states with the net spin scaling molecular size, which affords large tunability crucial for next-generation spintronics. However, scalable synthesis of ZTGMs and direct observation their long-standing challenges because molecules' high chemical instability. Here, we report bottom-up π-extended [5]triangulene atomic precision via surface-assisted cyclodehydrogenation a rationally designed precursor on metallic surfaces. Atomic force microscopy measurements unambiguously resolve its ZTGM-like skeleton consisting 15 fused benzene rings, while scanning tunneling spectroscopy reveal edge-localized electronic states. Bolstered by density functional theory calculations, our results show that [5]triangulenes synthesized Au(111) retain open-shell π-conjugated character magnetic ground