Synthesis of Alternating Copolymers with Substituents Containing Heteroatoms and the Regulation of Nontraditional Intrinsic Luminescence

Compared with other sequence structure polymers, alternating polymers usually have several unique properties, but their properties are more sensitive to changes in structure. By investigating the relationship between the structure and properties of alternating polymer chains, polymers with desired properties can likely be synthesized. In this study, a series of alternating copolymers of 1,1-diphenylethylene (DPE) derivatives and styrene derivatives, which exhibit nontraditional intrinsic luminescence (NTIL), are synthesized using living anionic polymerization. By changing the bridge plane structure of the DPE derivatives and the substituent groups of the styrene derivatives, the rigid chain structure of the alternating copolymers containing styrene derivative with a large steric hindrance is altered, and this change is observed by the altered fluorescence properties. Based on the results from experimental tests and theoretical simulations, copolymers with bridge plane structures have higher fluorescence emission intensities; moreover, a balance is observed between the electronic and steric hindrance effects of substituents on the fluorescence intensities, and polymer chains that are too rigid cause a decrease in the fluorescence intensities. Thus, the influence of the chain structure on the fluorescence properties of NTIL polymers cannot be disregarded.