Magnetism in organic materials

Summary form only given. Tailoring magnetic interactions of organic solids is currently an area of intense research activity. The cooperative efforts of chemists and physicists resulted in the preparation and analysis of a variety of new materials. Neutral monoradical solids and radical cation salts were used to study the variation of intermolecular exchange interaction with molecular packing and systematic molecular modifications (e.g. substituted triphenylverdazyls, perylene and tetraiodotetrathiafulvatene salts or charge transfer Complexes of C/sub 60). Intra and intermolecular exchange have been distinguished in di- and triradical systems (e.g. tri-triphenylverdazyl-benzene or molecules derived from well-known spin labels like nitronylnitroxides). Different metal-organic systems including charge transfer compounds were analysed; magnetism related to localized Manganese moments was observed in amorphous organic matrix, caused by Manganese in oxidic environment, or in charge transfer salts with TCNE and TCNQ. Besides chemical analysis and static magnetic susceptibility measurements in part ESR, NMR, ac susceptibility, specific heat and x-ray structural analysis were used to characterize these materials.