Porous Anionic Indium-Organic Framework with Enhanced Gas and Vapor Adsorption and Separation Ability

A three-dimensional microporous anionic metal-organic framework (MOF) (Et4N) 3[In-3(TATB)(4)] (FJI-C1, H(3)TATB= 4,4',4''-s-triazine-2,4,6-triyltribenzoic acid) with large unit cell volume has been synthesized. Assisted by the organic cation group Et4N in the pores of the compound, FJI-C1 not only shows high adsorption uptakes of C-2 and C-3 hydrocarbons, but also exhibits highly selective separation of propane, acetylene, ethane, and ethylene from methane at room temperature. Furthermore, it also exhibits high separation selectivity for propane over C-2 hy-drocarbons and acetylene can be readily separated from their C-2 hydrocarbons mixtures at low pressure due to the high selectivity for C2H2 in comparison to C2H4 and C2H6. In addition, FJI-C1 with hydrophilic internal pores surfaces shows highly efficient adsorption separation of polar molecules from nonpolar molecules. Notably, it exhibits high separation selectivity for benzene over cyclohexane due to the pi-pi interactions between benzene molecules and s-triazine rings of the porous MOF.