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

Abstract

Two ternary Ni(II) coordination polymers (CPs) named as: {[Ni2(L1)2(1,8-NDC)2(H2O)2]·2H2O}n (1), {[Ni2(L2)1.5(FA)(H2O)3]·3.75H2O}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, H4FA = 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 π–π 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. 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 π–π 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 radical plays a key effect in the efficient degradation of MB.