Toward Two‐Dimensional π‐Conjugated Covalent Organic Radical Frameworks

Reported is the synthesis, characterization, and material properties of the first π‐conjugated two‐dimensional covalent organic radical framework (CORF), PTM‐CORF , based on the stable polychlorotriphenylmethyl (PTM) radical. The covalent organic framework (COF) precursor ( PTM‐H‐COF ) was first synthesized by liquid/liquid interfacial acetylenic homocoupling of a triethynylpolychlorotriphenylmethane monomer, and showed crystalline features with a hexagonal diffraction pattern matching that of A‐B‐C stacking. Subsequent deprotonation and oxidation of the PTM units in PTM‐H‐COF gave PTM‐CORF . Magnetic measurements revealed that the neighboring PTM radicals in the PTM‐CORF are anti‐ferromagnetically coupled each other, with a moderate exchange interaction ( J =−375 cm −1 ). The PTM‐CORF has a small energy gap (ca. 0.88 eV) and a low‐lying LUMO energy level (−4.72 eV), and exhibits high electrocatalytic activity and durability toward the oxygen reduction reaction.