Synthesis, crystal structures and magnetic properties of copper(II) complexes with nitronyl nitroxide radicals

Two new copper(II) compounds with imino nitroxide radicals [CU(IM-MeImz)(2)center dot(SCN)] 0.5[Cu(SCN)(4)] (1) and [CU(IM-MeImz)(2)center dot(SCN)]ClO4-H2O (2) (IM-melmz = 2-(5-methylimidazol-4-yl)-4,4,5,5-tetramethyl-2-imidazoline- 1-oxyl) have been synthesized and characterized structurally and magnetically. X-ray analysis demonstrates that complex 1 contains Cu-II ions in both square-pyramidal and square planar coordination. There are complete charge separation into [Cu(IM-MeImz)(2)(SCN)](+) cations and 0.5[Cu(SCN)(4)](-) anions, in a 2:1 ratio. The complex 1 was connected as a one-dimensional polymer by intermolecular interactions. In complex 2, the coordination around the copper atom is distorted square pyramidal and the apical position is occupied by one nitrogen atom of SCN-anion. The 2-D network structure was formed and arranged through intermolecular H-bonds interactions. The complex I exhibits intramolecular weak ferromagnetic coupling between Cu-II ion and the radicals.