Cu(II) and Cd(II) coordination polymers derived from pyrazine-2,3-dicarboxylato and 1-vinylimidazole ligands: Synthesis, characterization and hydrogen storage capacities

Abstract

In this study, two new coordination polymers of Cu(II) and Cd(II) ions with pyrazine-2,3-dicarboxylic acid and 1-vinylimidazole were synthesized. The structures of these coordination polymers were characterized with elemental analysis, infrared spectroscopy, thermal analysis, powder X-ray dif-fraction, and magnetic susceptibility techniques. According to the results of the thermal analysis, the co-ordination polymers that contained water molecules decomposed below 100 °C, and the final products for both coordination polymers were the related metal oxides in an oxygen atmosphere. Powder X-ray dif-fraction analysis revealed that the coordination polymers were in the crystalline form. The hydrogen stor-age capacities and surface areas of the coordination polymers were also determined. The highest hydro-gen storage capacities were measured as 296 ml/g for the Cu(II) coordination polymer and 330 ml/g for the Cd(II) coordination polymer at approximately 75 bar and 75 K.