Precise control of the location and sequence of monomers in a narrow-disperse polymer chain remains a significant challenge. Our strategy uses selective and quantitative single additions of cyclopropene (CPE) derivatives to precisely place functional moieties at desired locations along a polymer chain during the living ring-opening metathesis polymerization (ROMP) of norbornenes (NBEs). In order to completely reinitiate the chain end after single addition of a CPE, we lowered the reaction temperature and added a labile ligand. Under our optimized conditions, we demonstrated the exclusive placement of single moieties at pre-determined locations along a polynorbornene (PNBE) homo or block co-polymer while maintaining narrow MW distributions and controlled MWs. Some polymers were used to synthesize precisely controlled branched architectures. The ability to control the location and number of individual functional groups in a polymer chain opens exciting opportunities for the precise synthesis and manipulation of polymer structures, architectures, assemblies, and properties.

精确控制窄分散聚合物链中单体的位置和顺序仍然是一个重大挑战。我们的策略是通过选择性和定量地添加环丙烯（CPE）衍生物，在降冰片烯（NBE）的活性开环易位聚合（ROMP）过程中，将功能性部分精确地沿着聚合物链放置在所需位置上。为了在单次添加CPE后完全重新引发链端，我们降低了反应温度并添加了不稳定的配体。在我们优化的条件下，我们展示了沿聚降冰片烯（PNBE）均聚物或嵌段共聚物沿预定位置排布的单个部分，同时保持了窄的MW分布和受控的MW。一些聚合物被用来合成精确控制的支链结构。