Two-dimensional coordination polymers of Zn(II) and Cd(II) derived from 3,3′,5,5′-azobenzenetetracarboxylic acid exhibiting solvent facilitated structure reversibility

摘要

Two Cd(II) and Zn(II) coordination polymers based on 3,3′,5,5′- azobenzenetetracarboxylic acid (H_4abtc): [Cd_2(abtc)(H _2O)_6]·DMF·0.5H_2O (1) and [Zn _2(abtc)(bpy)(H_2O)_2]·DMF·H _2O (2) are synthesized and structurally characterized. Both 1 and 2 are 2D polymers but interconnected by solvent molecules to generate 3D suprastructures. Solvent expulsion leads to rupture of both structures, but upon re-exposure to the solvent mixture they exhibit remarkable ability to regain the original structure reversibly from the almost amorphous solvent-expelled form. Compounds with such structural flexibility and reversibility are expected to have some useful functionality.