Ferromagnetic interactions in zinc(II) coordination complex containing nitronyl nitroxide radicals

A novel complex Zn(NIT2-py)3(ClO4)2(NIT2-py = 2-(2′-pyridyl)-4,4,5,5-tetramethyl-2-imidazoline-1-oxyl-3-oxide) (1) has been synthesized and characterized structurally and magnetically. The metal coordination sphere is fully occupied by three chelating nitroxide ligands, showing a distorted octahedral geometry. Temperature dependence of susceptibility measurements shows a weak ferromagnetic coupling between NIT2-py radicals with J = 2.13 cm−1. The field dependence of the magnetization further confirms that the ground state of the compound S = 3/2 results from ferromagnetic interactions within the complex 1.