Back Cover

A breakthrough in radical chemistry: stabilizing persistent radicals within covalent organic frameworks (COFs) to prevent annihilation via aggregation. Through thermal annealing—likened to "training in a burning tripod"—a backfolded alkyne‐rich COF ("junior monkey") is transformed into the radical‐rich COF ("Monkey King"). This material exhibits dramatically broadened intense absorption and superior photocatalytic oxidation of thioethers. By balancing stability with enhanced optical performance, this work opens new avenues for the rational design of radical‐rich materials. More details are discussed in the article by He et al . on pages 517—524. image