Magnetic Molecular Materials

One of the major challenges of science in the last few years of the second millennium is learning how to design materials which can fulfill specific tasks. Ambitious as it may be, the possibilities of success are not ne~li~ble provided that all the different expertises merge to overcome the limits of eXIsting disciplines and forming new paradigms science. The NATO Advanced Research Workshop on "Magnetic Molecular Materials" was organized with the above considerations in mind in order to determine which are the most appropriate synthetic strategies, experimental techniques of investigation, and theoretical models which are needed in order to develop new classes of magnetic materials which are based on molecules rather than on metallic or ionic lattices. Why molecules? The answer may be obvious: molecular chemistry in principle fine can tune the structures and the properties of complex aggregates, and nature already provides a large number of molecular aggregates which can perform the most disparate functions. The contributions collected in this book provide a rather complete view of the current research accomplishments of magnetic molecular materials. There are several different synthetic approaches which are followed ranging from purely organic to inorganic materials. Some encouraging successes have already been achieved, even if the critical temperatures below which magnetic order is observed still are in the range requiring liquid helium.

Contenu

LECTURES.- From Ferromagnetic Interactions to Molecular Ferromagnets: An Overview of Models and Materials.- Design of Molecular-Based Compounds Exhibiting a Spontaneous Magnetization; Strategies and Achievements.- An Approach to Organic Ferromagnets. Synthesis and Characterization of Polymers Due to 1-Phenyl-1,3-Butadyines Carrying a Substituent in Doublet or Triplet State on the Phenyl Ring.- Magnetic Coupling in High Spin Carbenes.- Intermolecular Ferromagnetic Coupling in Organic Radical Crystals.- Approaches to Magnetic Organic Materials.- Stable Polyradicals with High Spin Ground States.- Superdegeneracies and Orbital Delocalization in Extended Organic Systems.- Magnetism of Radical Cation Salts Based on the Organic Donor Tetramethoxy-Hexa-Meta-Phenylene.- Recent Advances in the Structure-Magnetic Coupling Relationship for Metallocene-Acceptor Based Electron Transfer Complexes.- Physics of the 1-D Molecular Ferromagnet Decamethylferrocenium Tetracyanoethanide, [DMeFc]+[TCNE]-.- Models for Magnetic Coupling in Metallocene Based Donor Acceptor Complexes.- Magnetic Properties of Some Biradicals of D2d (Or Approximate D2d) Symmetry, Extended-Dioxygen Analogs.- Coordination Chemistry of the Imino Nitroxides. Ferromagnetic Behavior of Some First Row Transition Metal Complexes.- Structural Magnetic Correlations in Phase Transitions of Molecular Magnets.- Magnetic Molecular Materials Containing Rare Earths.- Magnetism of Liquid Crystals.- Molecular Ferromagnetism in Organic and Inorganic Complexes; Influence of Orbital Effects.- The Edta Family of Molecular Based Ferromagnets.- Towards High Tc Ferro and Ferrimagnetic Bi and Tridimensional Materials from Molecular Precursors.- High Spin Inorganic Clusters: Spin Frustration in Polynuclear Manganese and Iron Complexes.- Exchange Interactions in Molecular Solids.- Magnetic and Optical Excitations in Clusters.- Frequency Dependent Susceptibilities of Magnetic Materials.- Spin Density of the Nitroxide Free Radicals 4.OL and 4.OXO 2,2,6,6 Tetramethyl Piperidyl 1-OXYL: Tanol and Tano.- REPORTS ON ROUND TABLES.- The Design Strategies.- Physical Investigation on Magnetic Molecular Materials.- Molecular Magnetic Materials. Applications.- Participants.