Cobalt(II) and Copper(II) Complexes Constructed from Bis(benzimidazole) and 2,6‐Pyridinedicarboxylate Co‐ligands: Synthesis, Crystal Structures, and Catalytic Properties

Abstract

Abstract Three metal complexes based on the flexible bis(benzimidazole) derivatives, namely [Co2(L1)4(pydc)2]·2H2O (1), {[Cu(L1)(pydc)]·0.75H2O}n (2), and [Co2(L2)2(pydc)2]·8H2O (3), [L1 = 1,2‐bis(5,6‐dimethylbenzimidazol‐1‐ylmethyl)benzene, H2pydc = 2,6‐pyridinedicarboxylic acid, L2 = 1,4‐bis(5‐methylbenzimidazol‐1‐ylmethyl)benzene] were hydrothermally synthesized and characterized by IR spectra, elemental analysis, UV/Vis diffuse refraction spectroscopy, and X‐ray single‐crystal diffraction. Complexes 1 and 3 exhibit a dinuclear structure composed of two central cobalt atoms bridged by flexible bis(benzimidazole) ligands and 3 finally packed into a two‐dimensional supramolecular network through π···π stacking interaction. Complex 2 shows a one‐dimensional zigzag chains motif, which further extended into a 2D supramolecular layer by face‐to‐face π···π stacking interactions. The luminescence properties of complexes 1–3 in the solid state at room temperature were described. Moreover, complexes 1 and 2 show higher catalytic activity than complex 3 for degradation of congo red azo dye in a Fenton‐like process.