Four new isostructural metal-organic frameworks constructed by a new butterfly-typed nitroheterocyclic carboxylic acid: Synthesis, crystal structures and properties

Abstract Four new isostructural coordination polymers, [M2(μ2-H2O)(DTBC)2] (CTGU- 26(M), M = Zn, Cd, Co and Ni] have been prepared with a new butterfly-typed nitroheterocyclic 4,6-di- 1H-1,2,4-triazol-1-yi-1,3-benzenedicarboxylic acid(H2DTBC) ligand and metal salts under hydrothermal condition. CTGU-26(Zn) features a unusual 2-nodal (4, 8)-connected scu topological network generated by [Zn2(μ2-H2O)(COO)4] units and DTBC2− anion linkers. Luminescent properties measurements indicate that both CTGU-26(Zn) and CTGU-26(Cd) show intense fluorescence-emission compared with free H2DTBC ligand in solid state. Moreover, the electrocatalytic activities of CTGU-26(Co) and CTGU-26(Ni) towards methanol oxidation reaction (MOR) of two compounds were also investigated. Remarkably, by combining each MOF with the conductive 2,3,6,7,10,11-hexahydroxytriphenylene(HHTP) additive, a composite material, HHTP/CTGU-26(Ni)–I was confirmed to have an excellent performance for MOR with a high mass specific peak current of 25.55 mA·cm−2.