Multi‐State Aromaticity: Aromatics in Both Ground and Lowest Excited States

Abstract Aromaticity represents one of the most significant and widely applied concepts in modern chemistry. According to Hückel's rules, cyclic conjugated rings with [4 n + 2] π electrons are aromatic in the ground state ( S 0 ) and anti‐aromatic in the lowest excited state (S 1 /T 1 ). Conversely, Baird's rule defines that cyclic molecules based on conjugated 4 n π π electrons exhibit anti‐aromatic and aromatic properties in S 0 and S 1 / T 1 , respectively. Do compounds showing aromaticity in both ground and lowest excited states─namely, multi‐state aromaticity, exist? This review presents the recent advances in the area and uncovers the tricks that make multi‐state aromaticity synthetically feasible.