Synthesis and properties of lanthanide(III) complexes containing pyridine-substituted imino nitroxide radical

Some lanthanide(III) complexes containing three types of a chelated n-methylpyridine-substituted imino nitroxide radical IMnMe2py(n=4,5,6) were synthesized with a small size of the multi-spin system. X-ray structural analysis of [Gd(hfac)(3)(IM6Me2py)], [Dy(hfac)(3)(IM4Me2py)] and [Dy(hfac)(3)(IM-5Me2py)] demonstrated that they are rigidly eight-coordinated with one IMnMe2py and three hfac ligands. Magnetic susceptibility measurements of the Gd(III) complexes indicate that the antiferromagnetic interaction between Gd(III) and imino nitroxide radical is different from the other lanthanide complexes containing nitronyl nitroxide radicals.