Nonconjugated Fumaric Acid-Based Polymers with Red-Emissive Clusteroluminescence

The practical utilization of clusteroluminogens (CLgens) is fundamentally constrained by their inherent limitations in short-wavelength emission and low quantum yield (QY). Although conventional heteroatom doping strategies can facilitate charge transfer states, they often introduce structural complexity and exacerbate nonradiative energy dissipation. In this study, a series of terpolymers were successfully synthesized using maleic anhydride, fumaric acid, and vinyl acetate through a one-pot free radical polymerization. This method preserved the advantages of a simple linear structure while containing only oxygen heteroatoms, thereby eliminating the need for intricate molecular designs and avoiding heavy atom effects. The saturated carbon chain structure of fumaric acid, in combination with the formation of intermolecular hydrogen bonding, effectively modulated the flexibility of the polymer chains, enhanced through-space interactions between molecular chains, and promoted the stacking effect of cluster groups. These synergistic effects enabled red light emission and bimodal emission characteristics with a high QY, demonstrating the potential for controllable emission wavelength tuning. This study, based on well-defined linear polymers, not only presents a new strategy for designing high-efficiency, long-wavelength-emitting CLgens through chain structure modulation and hydrogen bonding but also expands the practical applications of CLgens in light-converting films and encryption technologies.