Three new imidazole dicarboxylate metal compounds: Synthesis, structures, and magnetic property

Three new imidazole-based dicarboxylate metal compounds, {Ni(HMIDC)(bpp)}(n) (1), {[Ni-4(HEIDC)(4)(H2O)(8)]center dot H2O}(n) (2), and {Co-3(EIDC)(2)(py)(2)(H2O)(2)}(n) (3) have been synthesized and characterized by elemental analyses, IR, thermogravimetric analysis (TGA), and single-crystal X-ray diffraction (H3MIDC = 2-methyl-1H-imidazole-4,5-dicarboxylic acid; H3EIDC = 2-ethyl-1H-imidazole-4,5-dicarboxylic acid; bpp = 1,3-bis(4-pyridyl)-propane; py = pyridine). Compounds 1-3 show rich structural chemistry ranging from zero-dimensional, one-dimensional to two-dimensional structures. The Ni(II) centers were connected into a 1D chain in compound 1. Compound 2 is a tetranuclear Ni(II) cluster. In compound 3, MIDC3- coordinates to metal centers to form a 2D honeycomb-like layer. Variable-temperature magnetic susceptibility measurements indicate antiferromagnetic interactions between cobalt centers in compound 3.