NBN‐Doped Bis‐Tetracene and Peri‐Tetracene: Synthesis and Characterization

Combining solution‐based and surface‐assisted synthesis, we demonstrate the first synthesis of NBN‐doped bis‐tetracene (NBN‐BT) and peri‐tetracene (NBN‐PT). The chemical structures are clearly elucidated by high‐resolution scanning tunneling microscopy (STM) in combination with noncontact atomic force microscopy (nc‐AFM). Scanning tunneling spectroscopy (STS) characterizations reveal that NBN‐BT and NBN‐PT possess higher energy gaps than bis‐tetracene and peri‐tetracene. Interestingly, NBN‐BT can undergo stepwise one‐electron oxidation and convert into its corresponding radical cation and then to its dication. The energy gap of the NBN‐BT dication is similar to that of bis‐tetracene, indicating their isoelectronic relationship. Moreover, a similar energy gap between the NBN‐PT dication and peri‐tetracene can be predicted by DFT calculations. This work provides a novel synthesis along with characterizations of multi‐NBN‐doped zigzag‐edged peri‐acenes with tunable electronic properties. Two novel double NBN‐doped zigzag‐edged nanographenes, bis‐tetracene (NBN‐BT) and peri‐tetracene (NBN‐PT), are achieved through a combined in‐solution and on‐surface synthesis. The chemical structures are clearly characterized by STM and AFM. Moreover, NBN‐BT and NBN‐PT can be further tailored to dications, which demonstrate similar electronic properties to their all‐carbon‐based isoelectronic structures bis‐tetracene and peri‐tetracene.