Metal-Organic Frameworks Enable Spontaneous Singlet Oxygen Generation Without Light Irradiation

Singlet oxygen (¹O₂) is a widely used reactive oxygen species (ROS), making the development of new materials capable of efficiently generating it highly important. In this work, we report a series of isostructural metal-organic frameworks (MOFs), named JNU-300 (JNU = Jinan University), can spontaneously generate ¹O₂ by directly activating triplet oxygen (³O₂) from the air without the need for additional light irradiation. The highly selective generation of ¹O₂ by JNU-300 is verified by electron paramagnetic resonance (EPR) spectroscopy and probe experiments for ¹O₂. The generated ¹O₂ can be employed for aerobic oxidation of sulfide and antibacterial application. Mechanism studies revealed that the framework structure, and the adsorption and polarization of O₂ by the coordination units of JNU-300, are crucial for the ¹O₂ generation. To the best of our knowledge, MOFs JNU-300 are the first MOF material capable of producing ¹O₂ by activating ³O₂ in the absence of light at room temperature. This work provides new insights into the design and construction of functional MOF materials capable of generating ¹O₂ via activating ³O₂ without light irradiation, opening new possibilities for their application in specialized fields that require ¹O₂ in the dark.