Diazulenopentalene: Facile Synthesis of Linear Non-Alternant Molecular Carbons through Pt-Mediated Rearrangement.

Pentalene is a classic 8π antiaromatic non-alternant compound that displays high reactivity. To stabilize pentalene and investigate its properties, benzene rings are typically fused to its core. Advances in metal-catalyzed chemistry have rapidly accelerated the development of pentalene-incorporated molecular carbons. However, fully non-alternant structures based on the pentalene skeleton remain underexplored due to synthetic challenges. Here, we report the synthesis of a novel linear non-alternant hydrocarbon, diazulenopentalene, achieved via a Pt-mediated rearrangement arylation, with the mechanism elucidated by computational studies. Single-crystal analysis, complemented by aromaticity calculations, revealed that diazulenopentalene comprises distinct pentalene and azulene units. The synthetic strategy presented here provides a promising platform for a deeper investigation into this unique linear molecular carbon.