Cobalt‐Metalated 1D Perylene Diimide Carbon‐Organic Framework for Enhanced Photocatalytic <i>α</i> ‐C(sp ³ )─H Activation and CO ₂ Reduction

Abstract The photocatalytic activation of inert C(sp 3 )─H bonds in saturated aza ‐heterocycles provides a direct and efficient route to high‐value α‐amino amides but remains challenging due to intrinsically high bond dissociation energies. Herein, we report a cobalt‐metalated, one‐dimensional ABC‐stacking covalent organic framework ( PP‐COF‐Co ), integrating perylene diimide (PDI) as a photosensitizer and 1,10‐phenanthroline as a metal coordination site. Cobalt metalation significantly enhances photocatalytic efficiency, enabling the α ‐C(sp 3 )─H carbamoylation of saturated aza ‐heterocycles with yields of up to 91%, far surpassing its non‐metalated counterpart (59%). This enhancement arises from the synergistic interplay between the PDI units and cobalt centers, which promote electron‐hole pair separation and enhance singlet oxygen ( 1 O 2 ) generation. Moreover, PP‐COF‐Co exhibits a 57‐fold increase in photocatalytic CO 2 reduction activity compared to its pristine analogue. This work highlights the critical role of metalation in modulating charge dynamics within COF‐based photocatalysts and offers insights into the development of next‐generation materials for sustainable catalysis.