Crystallization‐Induced Emission Enhancements of Hybrid Butenolide‐Diphenylethenes

ABSTRACT Herein, we report crystallization‐induced emission enhancement (CIEE) from five hybrid butenolide‐diphenylethene derivatives. A combination of a flexible diphenylethene moiety with rigid butenolide core and specific electron‐donating and withdrawing substituents led to favorable solid‐state behavior in these simple molecules. Four derivatives ( BuPh , BuOMe , BuCN, and BuB r) exhibited enhanced fluorescence in crystalline state (Φ f ≤ 50%), while derivative BuCM showed dual‐state emission (DSE) with excellent Φ f of 90% in solution and good Φ f of 22% in solid‐state. Excitation‐dependent emissions were also seen for derivative BuPh . These results identify the butenolide–diphenylethene framework as a compact and readily accessible scaffold for CIEE and DSE‐active organic fluorophores.