Synthesis, crystal structure and magnetic properties of a cobalt(II) complex with pyridine-substituted imino nitroxide radicals

The mononuclear Co(im4-py)(4)(N-3)(2) complex** [im4-py = 2-(p-pyridyl)-4,4 ,5,5-tetramethylimidazoline-1-oxyl] has been synthesized and structurally c haracterized. It crystallizes in the triclinic space group P(1) over bar wi th the Co-II ion octahedrally coordinated and bound to four radical ligands through the nitrogen atom of the pyridine rings; the azido groups occupy t he apical positions. The complex exhibits weak intramolecular antiferromagn etic interactions between the Co-II ion and the imino nitroxide radicals; i ntermolecular antiferromagnetic interactions are observed.