Tunable Fluorescent Emission of Copolymers with Effects of Electron‐Withdrawing Groups

Abstract To development of long‐wavelength emissive nonconventional luminescent polymers remains a significant challenge. Herein, nonconjugated luminescent poly[(maleic anhydride)‐alt‐(vinyl acetate)] (PMV) derivatives with tunable emission wavelengths are achieved through a facile anhydride ring‐opening reaction by introducing electron‐withdrawing monomers. As the electron‐withdrawing capacity of the amine‐linked groups in the monomers increases, the strong donor‐acceptor (D‐A) interactions form between these groups and maleic anhydride (MAh) / vinyl acetate (VAc) enhance the quantity and intensity of n – π ^* and/or π – π ^* interactions, which narrow the HOMO‐LUMO energy gap between excited and ground states and thus result in a red fluorescent emission. PMV‐CPL (CPL: caprolactam) and PMV‐MAM (MAM: methacrylamide) exhibit long‐wavelength emission in solid and solution states, with emission maximum at 615 and 630 nm, respectively. Especially, the micro‐crosslinking effect of the double bond in PMV‐NVF (NVF: N‐vinylformamide) promotes the compact stacking between subunits, resulting in effective electron delocalization and sufficient conformational rigidity, achieving a quantum yield (QY) of 10.86% at 650 nm for red emission. This study also reveals the potential applications of PMV derivatives in white light‐emitting diodes and light conversion films.