Synthesis, Crystal Structures, and Photocatalytic Activity of Two Nickel(II) Coordination Polymers with Flexible Bis(benzimidazol-1-yl)alkane and Polycarboxylate Ligands

Two ternary Ni(II) coordination polymers (CPs) named as: {[Ni-2(L1)(2)(1,8-NDC)(2)(H2O)(2)]center dot 2H(2)O}(n) (1), {[Ni-2(L2)(1.5)(FA)(H2O)(3)]center dot 3.75H(2)O}(n) (2), (L1 = 1,6-bis(5,6-dimethylbenzimidazol-1-yl)hexane, L2 = bis(5,6-dimethylbenzimidazol-1-yl)methane, 1,8-H2NDC = 1,8-naphthalenedicarboxylic acid, H(4)FA = 4,4 '-(hexafluoroisopropylidene)diphthalic acid) were hydrothermally synthesized and characterized through physicochemical and spectroscopic methods. CP 1 features a 1D double straight-line chain and further extends into a 2D layers via pi-pi stacking interactions, while CP 2 shows a unique 2D (5,4,4)-connected network. The thermal stabilities, luminescence properties and photocatalytic activities of CPs 1-2 for methylene blue decomposition were also presented in detail. Graphic Two luminescent Ni(II) coordination polymers (CPs) were synthesized under hydrothermal condition. The crystal structure of CP 1 features a 1D double straight-line chain and further extends into a 2D layers via pi-pi stacking interactions, while CP 2 shows a unique 2D (5,4,4)-connected network. The photocatalytic experiments in the presence of catalysts CP 1 indicated higher degradation efficiency for MB solution than CP 2, and (OH)-O-center dot radical plays a key effect in the efficient degradation of MB.