A Cu(II) metal–organic framework based on an angular ligand with a bulky uncoordinated group: synthesis, structure, and gas adsorption

Abstract

By rational ligand desymmetrization and functionalization, a new angular ditopic carboxylate ligand with a bulky uncoordinated nitrophenyl group, 5′-(4-nitrophenyl)-[1,1′:3′,1″-terphenyl]-4,4″-dicarboxylic acid (H2NTDC), has been designed and synthesized. The smart H2NTDC ligand was employed to construct a novel metal-organic framework (MOF) [Cu(NTDC)(H2O)] (BUT-241, BUT = Beijing University of Technology) with the typical Cu-paddle-wheel SBU. Owing to the distinct geometry and functionality of the H2NTDC ligand, the 2-D (two dimensional) sql nets are packed via various π − π interactions. Therefore, the resulting structure of BUT-241 differs from other MOFs built with similar ligands. Through ligand engineering, the construction of BUT-241 has enriched the family of MOFs based on the classic ditopic carboxylate ligands. In addition, the nitrophenyl-functionalization also has an effect on the overall structure and pore chemistry of BUT-241, and thus facilitates its gas adsorption capacity.