Single‐Ion Magnets Based on Mononuclear Cobalt(II) Complexes with Sulfadiazine

The already reported monomeric complex Co(SDZ)(2)bpy (1) and the new ternary complex Co(SDZ)(2)(6MQ)(2) (2) (SDZ = sulfadiazine, bpy = 2,2'-bipyridine, and 6MQ = 6-methoxyquinoline) have been synthesized in order to study their magnetic properties. X-ray diffraction studies indicate that in both compounds the SDZ acts as a bidentate ligand coordinating through the sulfonamide and the pyrimidine N atoms giving rise to a CoN6 coordination sphere. The complexes have been characterized based on elemental analyses, FTIR, UV/Vis spectroscopy, and thermogravimetric analysis (TGA, only for 2). Compounds 1 and 2 have been characterized magnetically, and they show slow relaxation of the magnetization below 9 and 6 K, respectively.