Branched polymer synthesis is constrained by challenges such as monomer-specific reactivity limitations, multistep routes, and laborious purification, often yielding products with poorly controlled molecular weights and broad dispersity. To overcome these drawbacks, we designed a covalent organic framework bearing cyclic trinuclear copper(I) units (TFPP-Cu3 COFs) as a dual-functional platform for one-pot synthesis of branched polymers via orthogonal photo and thermal switching. This material efficiently catalyzes both photoinduced atom transfer radical polymerization (photo-ATRP) and copper-catalyzed alkyne–azide cycloaddition (CuAAC). Notably, for CuAAC, it achieves a turnover frequency of 86.8 h–1 and a mass specific activity of 320 mmol gcat–1 h–1, surpassing most reported heterogeneous catalytic systems. Under green light, it rapidly drives photo-ATRP to form well-defined polymer branches; switching to darkness and elevated temperature selectively activates CuAAC for grafting. Such orthogonal control enables streamlined, one-pot preparation of miktoarm star polymers without intermediate purification. The system demonstrates near-quantitative conversion, controlled molecular weight, narrow dispersity, and excellent catalyst recyclability, establishing a reproducible and modular strategy for precision synthesis and advancing multifunctional catalytic platform design.
Song et al. (Mon,) studied this question.