Eosin Y‑Containing Metal–Organic Framework as a Heterogeneous Catalyst for Direct Photoactivation of Inert C–H Bonds

Xanthene dyes as a class of ideal organic homogeneous photocatalyst have received significant attention in C–H bond activation; however, the inherent nature of fast carrier recombination/deactivation and low stability limits their practical applications. Herein, by the ingenious decoration of eosin Y into a porous metal–organic framework (MOF), a high-performance heterogeneous MOF-based photocatalyst was prepared to efficiently activate inert C–H bonds on the reactants via the hydrogen atom transfer pathway for the functionalization of the C–H bonds. Taking advantage of the fixation effect of a rigid framework, the incorporation of eosin Y into MOF leads to great enhancement of their chemical durability. More importantly, by the introduction of the second auxiliary ligand, the carbonyl groups of xanthene on the eosin Y dyes were perfectly retained and periodically aligned within the confined channels of this rigid framework, which could effectively form excited state radicals to prompt inert C–H bond activation, promoting reaction efficiency by the host–guest supramolecular interaction. New eosin Y-based MOFs were recyclable for six times without reducing photocatalytic activity. This eosin Y functionalized MOF-based heterogeneous photocatalytic system provides an availably catalytic avenue to develop a scalable and sustainable synthetic strategy for the practical application of organic dyes.