Metal–organic frameworks based on 4-(4-carboxyphenyl)-2,2,4,4-terpyridine: structures, topologies and electrocatalytic behaviors in sodium laurylsulfonate aqueous solution

Abstract

Using a novel rigid multitopic ligand, (4-(4-carboxyphenyl)-2,2,4,4-terpyridine) (HL), three novel metal–organic frameworks (MOFs) with formulae M₂L₂(1,4-bdc)(H₂O) (1,4-H₂bdc = 1,4-benzene dicarboxylic acid) (M = Co 1 and Ni 2) and Cu₂L₂(1,4-bdc)(H₂O)·2H₂O (3) have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction. MOFs 1 and 2 are isostructural and feature a novel 2-nodal (3,8)-connected three-dimensional (3D) architecture with a (4·6²)₂(4⁷·6¹⁸·8³) topology. MOF 3 comprises a novel 3-fold interpenetrated 3-nodal (3,4)-connected 3D framework with a (5²·8²·10²) (5²·8) (5⁴·8²) topology. MOFs 1–3 all show better solubilities in sodium laurylsulfonate (SDS) aqueous solution than in water. The three MOFs show different electrocatalytic behaviors for the H₂ evolution reaction in SDS solution, and MOF 1 shows better electrocatalytic properties in higher concentrations of SDS aqueous solution.