Coupling reactions between polymers are an important class of chemical modifications for changing, enhancing, and tuning the properties of polymeric materials. In particular, transformation of polymer topologies based on efficient, facile and less wasted coupling reactions remains a significant challenge. Here, we report coupling reactions based on electrochemical oxidation of 2,4,5-triphenylimidazole into a 2,4,5-triphenylimidazolyl radical and its spontaneous dimerization into hexaarylbiimidazole. Based on this chemistry, electrochemical topological transformation (ETT) and electrochemical chain extension have been realized with siloxane-based oligomers and polymers. Moreover, this approach enables one step ETT of star-shaped poly(dimethyl siloxane)s (PDMSs) into network PDMSs, running in an ionic liquid solvent and requiring no purification steps.

聚合物之间的偶联反应是一类重要的化学修饰，用于改变、增强和调整聚合物材料的性能。特别是，基于高效、简便且浪费较少的偶联反应来转换聚合物拓扑结构仍然是一项重大挑战。在这里，我们报告了基于 2,4,5-三苯基咪唑电化学氧化成 2,4,5-三苯基咪唑基自由基及其自发二聚成六芳基联咪唑的偶联反应。基于这种化学，电化学拓扑转变 (ETT) 和电化学扩链已通过基于硅氧烷的低聚物和聚合物实现。此外，这种方法使星形聚（二甲基硅氧烷）（PDMS）的一步 ETT 成为网络 PDMS，