Directional Electron Transfer in Porphyrin‐Based Heteroleptic Metallacages for Enhanced Visible Light‐Driven Photocatalysis

Abstract

Abstract The rational design of supramolecular architectures capable of mediating directional photoinduced electron transfer (PET) remains a central challenge in confined photocatalysis. Herein, we report two porphyrin‐based heteroleptic metallacages, constructed via multicomponent coordination‐driven self‐assembly, for the visible light‐driven oxidative coupling of tetraorganoborates. Both metallacages feature well‐defined, positively charged cavities that enable selective substrate encapsulation and efficient catalytic turnover. In particular, one metallacage incorporates electron‐rich triphenylamine units that engage in directional interligand PET with the porphyrin moieties, as supported by femtosecond transient absorption spectroscopy and density functional theory calculations. This intramolecular PET promotes long‐lived charge separation and enhances superoxide anion generation, resulting in markedly improved photocatalytic activity compared to control systems lacking donor–acceptor motifs. This study demonstrates a modular strategy for integrating electron donor and acceptor functionalities within a single supramolecular scaffold and highlights the potential of PET‐enhanced cage‐based photocatalysis, providing a versatile platform for sustainable light‐driven chemical transformations.