Auxiliary ligand-assisted structural diversities of three metal–organic frameworks with potassium 1H-1,2,3-triazole-4,5-dicarboxylic acid: syntheses, crystal structures and luminescence properties

Abstract

Three metal–organic frameworks (MOFs) with d10 metal ions, namely, {[Zn3(TDA)2(bpy)3]·(bpy)·10.5H2O}n (1), {[Zn3(TDA)2(azopy)2.5(H2O)]·4H2O}n (2) and {[Cd2K3(TDA)(HTDA)2(H2O)4]}n (3) (KH2TDA = potassium 1H-1,2,3-triazole-4,5-dicarboxylic acid, bpy = 4,4′-bipridine, azopy = 4,4′-azobispridine), have been successfully synthesized from KH2TDA with the aid of three different length-controllable auxiliary ligands and characterized by infrared spectra, elemental analysis, thermogravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. MOF 1 shows an interesting three-dimensional (3D) (3,4,4,4)-connected KAVGAQ framework with a Schläfli symbol of {63}2{64·102}{64·82}2, which can be extended by 2D layers and bpy pillars. MOFs 2 and 3 also display 3D framework structures, corresponding to a 6-connected {44·611} net and a (6,12)-connected {312·430·520·64}{36·48·5} net, respectively. Moreover, a novel coordination mode of H3TDA is observed in 3. The luminescence properties of 1–3 are investigated.