Effect of flexibility of organic dicarboxylates anions on the four 3D metal-organic frameworks constructed from flexible benzimidazolyl-based ligand

► Complexes 1 and 2 are eight-connected net with 42464 topology. ► Complexes 3 and 4 are (4,4)-connected net with meso-helical chains. ► The structural differences indicate the importance of organic dicarboxylates anions. ► The thermal stability and voltammetric behavior of complexes 1-4 have been studied.