A new gadolinium complex with 1, 3-bis (carboxymethyl) imidazolium chloride ionic liquid: Solvothermal synthesis, structure and magnetic properties

A new 3D complex namely [Gd4(C7H7N2O4)6(H2O)12]·Cl6·9H2O (1) was solvothermally synthesized by using 1,3-bis (carboxymethyl) imidazolium cation as a ligand. Single crystal X-ray analysis reveals that 3D positive charged framework was formed by Gd–O coordination bonds,and Gd3+ ions have two kinds of coordination environments. The free counter Cl− ions and lattice H2O locate in cavities of 1 through extensive H-bonds and electrostatic attractions between the Cl−/H2O and the positive framework. The thermogravimetric analysis (TGA) shows the organic framework decomposed at temperature above 345 °C, giving the final products Gd2O3. The temperature dependent magnetic susceptibility displays antiferromagnetic interaction at temperature below 15.2 K, once above 15.2 K, compound 1 converts into paramagnetic interaction.