Aza-Triangulene: On-Surface Synthesis and Chemistry

On-surface synthesis (OSS) has enabled the fabrication and characterization of a myriad
of π-magnetic molecular materials. 1 Recently, we showed that N-substitution of triangulene, towards aza-triangulene, leads to substrate-induced switching of electronic states. 2 Opposite directions of charge transfer led to a cationic open-shell triplet on Au(111) and a closed-shell anion on Ag(111). These differences were then exploited to produce fused dimer derivatives on the respective substrates. 3 All products were characterized by high-resolution scanning tunneling microscopy and spectroscopy (STM & STS) and supported by DFT. The presentation will conclude with insights to the design 4 and future prospects of organic carbon-based radicals.