A functional anionic metal-organic framework for selective adsorption and separation of organic dyes

A 3D porous anionic MOF, {[CH3)(2)NH2][Zn-6(mu(3)-OH)(mu(4)-O)(NSBPDC)(5)(H2O)(2)]center dot DMF center dot 12H(2)O}(n) (Zn-1) (H2NSBPDC = 6-nitro-2,2'-sulfone-4,4'-dicarboxylic acid), has been synthesized and characterized. Zn-1 exhibits a rare 5-connected 'sqp' net and contains large 3D intersecting channels modified with functional groups. Notably, Zn-1 can adsorb cationic dyes selectively and effectively, even for large molecules including Rhodamine B and Crystal Violet. The influences of the constant time and initial concentration of MB on the adsorption capacity of Zn-1 have been studied in detail. Furthermore, the kinetic research indicates that the adsorption of MB matches well with the pseudo second-order model. In addition, the material of Zn-1 is reusable, and the adsorbed dye (MB) can be released in saturated DMF/ethanol solution of LiNO3. (C) 2018 Elsevier Ltd. All rights reserved.