Direct C-H bond activation using visible light and a donor-acceptor polymer with tunable valence band

Abstract Currently, converting hydrocarbons into high-value-added products through photocatalytic selective activation under mild conditions is attractive and challenging, motivating research efforts to explore inexpensive and efficient photocatalysts. Here, we report a donor-acceptor polymer with tunable valence band to trigger direct photocatalytic C-H bond activation for selective oxidation, halogenation and coupling reactions using visible light and air without the assistance of any sacrificial additives. Apart from the fast charge separation driven by donor-acceptor pairs, both experimental and theoretical results have demonstrated that the downshifted valence band of the polymer photocatalyst dominated the enhanced oxidation power to accelerate C-H bond activation. resulting in the best-in-class catalytic performance of paraxylene oxidation with high aldehyde selectivity (> 99%), outperforming the state-of-the-art metal-free homogeneous catalysts in the literature by a factor of 4.