Synthesis of fluorescent hyperbranched enediynes and Bergman cyclization polymerization for generating spatially locked persistent radicals

Bergman cyclization of hyperbranched enediynes for generating spatially locked persistent radicals. HBPs with embedded enediyne moieties and many iodine groups in the peripheral are synthesized through one-pot Sonogashira cross coupling reaction of AB2-type monomers and functionalized by modification with phenylacetylene to get a series of fluorescent HBPs (HBEPs). The HBEPs are further subjected to thermal Bergman cyclization, producing polymeric networks with abundant free radicals locked inside, which are stable for a long time at room temperature, and can be slowly quenched when exposed to air.134