Dimensional and Isomeric Effects of Pyrene-Based Covalent Organic Frameworks on PET-RAFT Polymerization

Covalent organic frameworks (COFs) are crystalline, porous semiconductors that have attracted significant interest in photocatalysis. The double chain edge structure of one-dimensional (1D) COFs enhances stability and minimizes energy loss, while varying linkage orientations create diverse optical band gaps and charge transfer properties. However, dimensional and isomeric COFs are rarely explored in photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization, leaving their structure-activity relationships unclear. Herein, we synthesized 1D TA-COF, 1D TF-COF, 2D TA-COF, and 2D TF-COF to evaluate their behavior in oxygen-tolerant PET-RAFT polymerization. Notably, 1D TA-COF demonstrated optimal photocatalytic performance (79.4%, 16 h) owing to efficient charge separation, while isomeric 1D TF-COF exhibited lower productivity (41.5%) due to hindered electron transfer. Additionally, 2D TF-COF outperformed 2D TA-COF (51.0% vs. 36.7%, 16 h), highlighting the considerable impacts of dimension and isomerism on performance, with dimension playing a more dominant role due to the electron delocalization characteristics determined by topological structure.