Two different dimensional bbbm-based cobalt(II) coordination polymers tuned by benzenedicarboxylates: Assembly, structures and properties

Two new metal–organic coordination polymers [Co4(bbbm)4(1,2-BDC)4(H2O)]·2H2O (1) and [Co(bbbm)(1,4-BDC)] (2) (bbbm = 1,1-(1,4-butanediyl)bis-1H-benzimidazole, 1,2-H2BDC = 1,2-benzenedicarboxylic acid and 1,4-H2BDC = 1,4-benzenedicarboxylic acid) were obtained under hydrothermal conditions and structurally characterized. Polymer 1 exhibits a two-dimensional (2D) 4-connected network with the CoII ions as four-connected nodes, and the bbbm and 1,2-BDC ligands as linkers. Polymer 2 possesses a novel three-dimensional (3D) 3-fold interpenetrated framework. The position of carboxyl groups for benzenedicarboxylates dominates the final structures of 1 and 2. Furthermore, elemental analysis, IR spectroscopy, thermogravimetric analysis, electrochemical properties and solid state fluorescence for 1 and 2 were investigated.