Magnetic properties of the single crystals of layered Cu(II) and Co(II) complexes with 3-imidazoline nitroxides

Single crystals of Cu(II) and Co(II) complexes with stable nitroxides 4-(2' -ethoxycarbonyl-2'-oxoethylidene)-2,2,5,5-tetramethyl-3-imidazoline-1-oxyl (HL1) and 4-(2'-methoxycarbonyl-2'-oxoethylidene)-2,2,5,5-tetramethyl-3-imi dazoline-1-oxyl (HL2) have been investigated by the static magnetic suscept ibility method. It was found that bulk ferromagnetic ordering is inherent i n layered CuL2I and alpha-CuL22 at similar to 5 K. Easy magnetization axes were determined for both compounds. At the same time,the complex beta-CuL22 , possessing a molecular structure, does not show noticeable anisotropy in the region 2-300 K. For the layered complex CoL2I, the magnetic transition temperature, if any, is lower than 2 K. In the whole range 2-300 K, the sin gle crystals of CoL21 show a rather high anisotropy of magnetic susceptibil ity.