Porous framework materials for singlet oxygen generation

Singlet oxygen (1O2) is an excited state of the dioxygen molecule with higher reactivity compared to the ground electronic state. Therefore, singlet oxygen is an important species used for oxidation of organic compounds, degradation of environmental pollutants, inactivation of bacteria or treatment of tumours. Metal-organic frameworks (MOFs) are suitable as carriers of 1O2 photosensitizers because of the permeability of their porous structure to gas molecules and effective prevention of aggregation of the photosensitizer chromophores. Moreover, the character of MOFs enables easy preparation of multifunctional materials combining 1O2 generation with other properties. In this review we summarize recent advances in the development of MOFs for 1O2 generation. We focus on the three main fields of application of these materials: oxidation of organic compounds, degradation of pollutants and photodynamic therapy. Each of these fields has its own specific requirements, which is reflected in the design of appropriate materials.