Gas Storage in a Partially Fluorinated Highly Stable Three-Dimensional Porous Metal–Organic Framework

Abstract

A partially fluorinated linear rigid linker, 2,2'-bis-trifluoromethyl-biphenyl-4,4'-dicarboxylic acid (H2bfbpdc), has been synthesized. This linker forms a porous three-dimensional (3D) metal-organic framework, {[Zn4O(bfbpdc)3(bpy)0.5(H2O)]·(3DMF)(H2O)}n (1), in the presence of the colinker 4,4'-bipyridine (bpy) and Zn(NO3)2·6H2O under solvothermal condition. Single crystal X-ray analysis shows that 1 contains a 3D channel structure with highly polar pore surfaces decorated with pendant trifluoromethyl groups of bfbpdc(2-) linker. Thermogravimetric analysis (TGA) and variable temperature powder X-ray diffraction (VTPXRD) exhibit high thermal stability of the framework. The solvent molecules present in the voids can be removed by heating, maintaining the integrity of the structure to afford a porous framework. Gas (N2, H2, CH4, and CO2) and water adsorption studies were performed on this framework.