Magnetic properties of isomeric N,N′-di-(2,2,6,6-tetramethylpiperidin-1-oxyl-4-yl)xylyl imine

Three novel isomeric N,N′-di-(2,2,6,6-tetramethylpiperidin-1-oxyl-4-yl)xylyl imine (compounds 1, 2 and 3) were prepared and their structures were determined by X-ray single-crystal diffraction (except compound 1). ESR spectra were measured at room temperature. Temperature dependences of magnetic susceptibility down to 5 K for the organic biradicals 2 and 3 are described. The Weiss constants for compounds 2 and 3 are 0.2 and −0.03 K, respectively. The small differences in the magnetic properties of compounds 2 and 3 might arise from the isomeric difference in the molecular structure.