Том 56, № 4 ЖУРНАЛ СТРУКТУРНОЙ ХИМИИ Июль UDC 548.73:547.13:546.73 A NEW 2D COBALT(II) COORDINATION POLYMER CONSTRUCTED FROM 1,2,4,5-BENZENETETRACARBOXYLATE AND FLEXIBLE BIS(BENZIMIDAZOLE) LIGANDS X. Du, R. Yang, X.X. Wang, G.H. Cui College of Chemical Engineering, Hebei United University, Tangshan, Hebei Province, P. R. China E-mail: tscghua@126.com Received September 16, 2013 A new 2D cobalt(II) coordination polymers namely {[Co2(btec)(L)2]⋅4H2O}n (1), where btec = = 1,2,4,5-benzenetetracarboxylate and L = 1,3-bis(5,6-dimethylbenzimidazol-l-yl)-2-propanol, are hydrothermally synthesized and characterized by elemental analyses, IR spectroscopy, and single crystal X-ray diffraction analyses. <...> The complex possesses a binodal (3,4)-connected two-dimensional layered structure bridged by btec and L ligands. <...> The fluorescence and catalytic properties of the complex are also investigated. <...> It is well known that the coordination geometries of the metal centers and the coordination behavior of organic ligands are the main keys to achieve the target coordination polymers. <...> Benzene-based multicarboxylic acid ligands have been widely used as good candidates for the construction of coordination polymers [ 7—9]. <...> For example, 1,2,4,5-benzene tetracarboxylate (btec) has various coordination modes to metal ions, resulting from completely or partially deprotonated sites, which allows for the diversity of framework topologies of MOFs. <...> On the other hand, the most prominent compound of benzimidazole derivatives is 5,6-dimethylbenzimidazole, which serves as an axial ligand for cobalt in vitamin B12 [ 10—13]. <...> To the best of our knowledge, coordination polymers based on flexible bis(5,6-dimethybenzimidazole) and multicarboxylic acid ligands have only been scarcely studied [ 14—16 ]. <...> In this report, we focus our continuing efforts on coordination polymers based on flexible bis(5,6-dimethybenzimidazole) ligands [ 17—20 ]; here we report the preparation, crystal structure, and fluorescence properties of a new two-dimensional framework {[Co2(btec)(L)2]⋅4H2O}n (1) L = 1,3-bis(5,6-dimethylbenzimidazol-l-yl)-2-propanol). <...> All the solvents and reagents for the synthesis were purchased from Sigma—Aldrich unless otherwise specified and used as received. <...> The ligand L was prepared according to the literature method with a minor <...>