The development of multi-functional materials as physical adsorbents for gas storage and dye adsorption is of utmost importance for ecological environment management. Ionic metal-organic frameworks (MOFs) with exchangeable counterions would easily be modified to enhance their performance. Herein, we report a novel {Zn 5 }-based MOF (SDU-CP- 2 ) with the dimethylamine cation [(CH 3 ) 2 NH 2 ] + in its crystal structure, which can be readily exchanged with Li + ions and cationic dyes. Consequently, it exhibits high CO 2 and C 2 H 2 adsorption capacities as well as charge/size-selective adsorption of dye molecules. The adsorption of SDU-CP- 2 toward cationic dyes was confirmed to be efficient in terms of recyclability and ion-exchange mechanisms. The column filler experiment and high water stability decisively supported its potential application in waste water treatment.