Spatial Electronic and Thermal Microenvironment Engineering of POMOF to Boost Photothermal C–N Cross-Coupling Catalysis

Abstract Photothermal synergistic catalysis has emerged as a powerful strategy for boosting C–N cross-coupling reactions, yet the rational design and precise fabrication of efficient crystalline catalysts with integrated photo- and thermal-responsive properties remain highly desirable. In this work, a highly photothermal synergistic catalyst {[H2Cu4(DPA)6(H2O)4][BW12O40]}·[BW12O40]·2DPA·2H2O (denoted as CuBW–DPA) was assembled by integrating a D-A type ligand 9,10-di(pyridin-4-yl)anthracene (DPA), Cu ions, and [BW12O40]5– into an ordered framework structure, which effectively enhances broad-spectrum light absorption and energy transfer efficiency, achieving high photothermal conversion performance. DPA with an anthracene-based moiety as an electron donor efficiently activates molecular oxygen (O2) to generate endoperoxides (EPOs) as reactive oxygen species, enabling the dynamic release of singlet oxygen (1O2). Meanwhile, the electron-sponge polyanion [BW12O40]5– was immobilized within the framework and acts as an electron acceptor to extend the material’s absorption in the near-infrared region. Strong spin–orbit coupling facilitates intersystem crossing (ISC). In addition, the high-frequency vibrations of the POMOF enable rapid dissipation of excited-state energy into heat via vibrational relaxation. In comparison with MOF Cu–DPA, CuBW–DPA reaches a maximum temperature of 110 °C under 0.8 W near-infrared irradiation. Subsequently, CuBW–DPA was applied in the photothermal catalytic C–N coupling reaction for the efficient synthesis of paracetamol, melatonin, and moclobemide. It is noteworthy that the photothermal synergistic catalysis enables the reaction to complete within 1 hour, greatly improving the reaction efficiency. Moreover, this cross-coupling reaction can be performed under continuous-flow conditions, affording 2.1 g of paracetamol in a single run. The photocatalytic mechanism was further verified by in situ X-ray photoelectron spectroscopy (XPS) and in situ electron paramagnetic resonance (EPR) measurements.