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Non‐benzenoid polycyclic aromatic hydrocarbons (PAHs) have received a lot of attention because of their unique optical, electronic, and magnetic properties, but their synthesis remains challenging. Herein, we report a non‐benzenoid isomer of peri‐tetracene, diazulenorubicene (DAR), with two sets of 5/7/5 membered rings synthesized by a (3+2) annulation reaction. Compared with the precursor containing only 5/7 membered rings, the newly formed five membered rings switch the aromaticity of the original heptagon/pentagon from antiaromatic/aromatic to non‐aromatic/antiaromatic respectively, modify the intermolecular packing modes, and lower the LUMO levels. Notably, compound 2 b (DAR‐TMS) shows p‐type semiconducting properties with a hole mobility up to 1.27 cm2 V−1 s−1. Moreover, further extension to larger non‐benzenoid PAHs with 19 rings was achieved through on‐surface chemistry from the DAR derivative with one alkynyl group. [ABSTRACT FROM AUTHOR]

Frontispiece: Diazulenorubicene as a Non-benzenoid Isomer of peri-Tetracene with Two Sets of 5/7/5 Membered Rings Showing Good Semiconducting Properties Keywords: Annulation; Aromaticity; Fused Ring Systems; Semiconducting Properties; on-Surface Synthesis EN Annulation Aromaticity Fused Ring Systems Semiconducting Properties on-Surface Synthesis 1 1 1 09/20/23 20230925 NES 230925 B Organic Semiconductors b . In their Research Article (e202304632), Xi-Sha Zhang, Deqing Zhang et al. report a (3+2) annulation reaction to synthesize diazulenorubicenes showing semiconducting properties. [Extracted from the article]