Structural modulation of Co(II) coordination polymers with flexible bis(benzimidazole) and different dicarboxylate ligands

Two complexes [Co-2(L)(2)(nPht)(2)center dot H2O](n) (1) and [Co(L)(miP)center dot 0.5H(2)O](n) (2) (H(2)npht = 3-nitrophthalic acid, L = 1,3-bis(5,6-dimethylbenzimidazol)propane, H(2)mip = 5-methylisophthalic acid) were obtained under hydrothermal conditions. In compound 1, two npht(2-) ligands connect two crystallographically independent Co atoms to form a binuclear [Co-2(npht)](2) subunit, further linked by L ligands to generate a 1D ladder-like chain, which is arranged into a 2D supramolecular layer through face-to-face pi-pi stacking interactions. Compound 2 exhibits a 2D 4-connected coordination network. The fluorescence properties of 1 and 2 have been investigated in the solid-state. Both complexes show higher catalytic behaviors for degradation of methyl orange dye. (C) 2013 Elsevier B.V. All rights reserved.