Symmetry, nitroxide radicals

The family of nitronyl nitroxide (4,4,5,5-tetramethyli-midazoline-l-oxyl 3-oxide) derivatives has been shown to constitute a treasure house of organic magnetism. The derivatives form very stable crystals of various types of symmetry. Table 15.1 compiles the crystallographic data of the nitronyl nitroxide derivative studied in our laboratories. Nitronyl nitroxides often exhibit intermolecular ferromagnetic (FM) interactions as well as antiferromagnetic (AFM) interactions. Furthermore, the interactions are zero-, one-, two- or three-dimensional (OD, ID, 2D or 3D) as a result of various kinds of crystal structures. Thus this group of radicals exhibits a variety of magnetisms. 

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