Selectivity-Enhanced Near-Infrared Photocatalytic Dehydrogenation and C─N Coupling via Lanthanide Nanocrystal-Mediated Photosensitization

Abstract

Near-infrared (NIR) light-driven photocatalysis provides a promising solution to the inherent limitations of conventional ultraviolet (UV) and visible-light photocatalysis, such as shallow penetration, photodamage from high-energy irradiation, and limited selectivity. However, effective strategies for achieving NIR photocatalysis remain scarce. Here, a novel strategy that achieves NIR photocatalysis with significantly enhanced selectivity is reported through lanthanide nanocrystal-mediated photosensitization. A composite nanocatalyst, comprising NaNdF₄ lanthanide nanocrystals and Zn(II) phthalocyanine organic photosensitizers is designed, where the NaNdF₄ absorb 808 nm NIR light and transfer energy directly to the photosensitizers via lanthanide-mediated triplet sensitization. This approach enables selective functionalization of organic substrates with increased yields and reduced side-product formation compared to UV/visible light excitation. The enhanced selectivity arises from the controlled generation of superoxide anions (O₂⁻) as reactive oxygen species (ROS) and minimized substrate photoactivation. The approach enables targeted dehydrogenation and C─N coupling reactions of diverse N-heterocyclic substrates, including halogen-substituted compounds that are typically prone to undesired side reactions. The findings establish a versatile strategy for improving selectivity in photocatalytic transformations, opening new opportunities in light-sensitive organic synthesis and sustainable catalysis.