This award to Prof. Paul Lahti at the University of Massachusetts-Amherst is supported by the Advanced Materials and Processing Program in the Chemistry Division. The theme of the research is the synthesis, characterization and performance of molecular organic assemblies with multiple unpaired electrons as magnetic materials. Structural alterations will be developed in both polymeric arrays and solid state crystalline arrays which optimize interactions among the unpaired electron spins. Specifically, polymeric free radical systems will be made which maximize planarity, stable free radicals systems which interact through hydrogen bonded assemblies will be investigated, and free radical systems that assemble through metal chelation will be studied. The stable free radical types employed will be nitronyl nitroxides, iminoyl nitroxides and benzonitroyl nitroxides. Characterization will be by elemental analysis, ESR, NMR and GC-MS. Magnetic performance measurements will be carried out through established collaborations. This highly interdisciplinary research addresses fundamental mechanisms of organic ferromagnetism based on long range assembly of electronic spins. The combination of organic synthesis, stable free radical characterization, and magnetic performance measurements will provide an ideal environment for the training of students in problems of both fundamental interest and technological relevance. Additionally, many of the precursor and free radical species involved may have medicinal and pharmacological activity and will be made available for biological screening.