Decoration and utilization of a special class of metal–organic frameworks containing the fluorine moiety

Fluorinated organic molecules are generally chemically stable and have low electric polarizability because of the high electronegativity of fluorine. The use of fluorinated organic and inorganic molecules to synthesize innumerable coordination compounds, such as metal–organic frameworks (MOFs), has had a significant effect on the field of material chemistry. The high electronegativity of the fluorine atom attached to the organic ligand/linker generates electropositive character on the other part of the linker. This electropositive character of the ligand means that it can easily interact with electron-rich guest molecules in different host–guest applications. The metal complex formed with these fluorinated moieties generates an electron-dense pore environment owing to the existence of fluorine atoms inside the voids. These properties make fluorinated MOFs (FMOFs) potential candidates to provide a range of properties, such as particular chemical adsorption sites and host-material flexibility. FMOFs are generally hydrophobic because of the existence of fluorine atoms inside the pores, which aids in removal of oil spills on water and adsorption/separation of different gases and hydrocarbons. The high chemical and aqueous stability of FMOFs make them excellent candidates for many applications under various conditions. The fluorine-lined channels of FMOFs show excellent affinity for gas molecules, and they can thus be used for gas storage/separation. Owing to these unusual properties, FMOFs have been widely used as gas-separation materials and for removal of hazardous impurities from aqueous systems. Herein, we review synthesis of FMOFs using different strategies, the characteristics of FMOFs, and the applications of FMOFs in various fields, including gas adsorption/separation, hydrocarbon adsorption/separation, dye adsorption, catalysis, and sensing of small molecules.