Аннотация:Abstract A three‐dimensional microporous anionic metal–organic framework (MOF) (Et 4 N) 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 Et 4 N 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 hydrocarbons and acetylene can be readily separated from their C 2 hydrocarbons mixtures at low pressure due to the high selectivity for C 2 H 2 in comparison to C 2 H 4 and C 2 H 6 . 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 π–π interactions between benzene molecules and s ‐triazine rings of the porous MOF.