Synthesis of Hyperbranched Polyenediynes with Maleimide Moieties

Three kinds of AB₂ type monomers with terminal alkyne (A) and iodine (B) were synthesized from dichloromaleic anhydride by amidation with terminal alkynyl amine followed by chlorine-iodine exchange reaction. Starting from these AB₂ monomers, a series of hyperbranched polymers with enediyne repeating unit (HBEPs) were synthesized via one-pot Sonogashira cross coupling polymerization reaction. The structure of these HBEPs was characterized by NMR, FT-IR, GPC, DLS, DSC, UV-Vis and fluorescence spectroscopy. The effects of substituents of backbone on the physical and chemical properties of these polymers were studied. Results show that the maximum degree of branching of HBEPs is close to 1. In addition, the fluorescence characteristics of HBEPs are related to its conjugation degree.