Synthesis, Crystal Structures, and Thermal Properties of Two Ni(II) Supramolecules Constructed from Imidazole Dicarboxylates

Treatment of two kinds of imidazole dicarboxylate ligands, 1-(carboxymethyl)-1,3-benzimidazol-3-ium-3-acetate (HL1) and 2-methyl-1H-imidazole-4,5-dicarboxylic acid (H3L2), with Ni2+ ions resulted in two supramolecular complexes [Ni(L1)2(H2O)4] (1) and [Ni(H2L2)2(H2O)2] (2), respectively. Their crystal structures have been characterized by single-crystal x-ray determinations. There are three kinds of components in the two complexes: metal ions, imidazole carboxylate units and water molecules. The thermal properties of the two complexes have been determined as well.