R. Cava et al. Progress in Solid State Chemistry 30(2002)1-101 1. 5. Molecular. hybrid, and macromolecular materials The design, preparation, and study of physical properties of molecular assemblies nd polymeric molecule-based materials exhibiting useful magnetic, electrical, or optical properties is a very active area of worldwide research. The quest in this area is not just to obtain molecule-based compounds than can behave like classical materials, but also to produce materials that may exhibit completely new physical properties or those in which several properties are combined. Examples of such sys- tems could be materials showing electrical or magnetic bistability, tunable magnetic ordering temperatures, discrete molecules showing magnetic hysteresis (nanomagnets), and hybrid materials coupling more than one property, e.g. magnet- ism with conductivity/superconductivity, or magnetism with optical properties. Other interesting phenomena that may be studied are quantum tunneling effects, long-live hoto- optical excited states, and solids with restricted magnetic dimensionalities One frontier area in this research field is the evolution of new synthetic strategies to construct molecules at the mesoscale level and to specifically control their organi zation in solution and/or in the solid state. This includes the formation of thin layers and organized films, or their encapsulation/intercalation, etc, into solids. A second key area is the application of frontier experimental techniques to characterize the resulting materials and allow for the identification of the most interesting phenomena Finally, it is important to develop suitable theoretical models based on solid-state approaches as well as on molecular orbital approaches(ab initio and density func tional theory). The ultimate goal is an understanding of the properties of the materials that will lead to predictions about the nature of interactions in molecular/macromolecular assemblies. All these areas of research have been. and continue to be, of great interest in the study of the solid state chemistry of non- molecular compounds. There is an immeasurable potential benefit to both the solid state chemistry and molecular chemistry communities in greatly increasing the inter actions between these two areas of research The structural and chemical diversity of molecular compounds is unparalleled in the world of solid state chemistry. Mor be syr sized by rational synthetic strategies that are impossible to implement in the solid state. In light of these attributes, molecular compounds present almost unlimited possibilities for development of new materials with novel and complex physical properties. The potential for fruitful interactions with the solid state chemistry com munity also appear to be limitless, as molecular chemists become increasingly inter ested in the synthesis of new compounds with exotic magnetic and electronic proper ties and the correlation of those properties with chemistry and structure-areas of research that are at the very heart of traditional solid state chemistry. This section describes the potential for interactions in the areas of molecular precursor routes to materials, self-assembled and organic materials, molecular nanomagnets, composite and hybrid molecular materials (such as templated materials)and finally inorganic/organic hybrid materialsR.J. Cava et al. / Progress in Solid State Chemistry 30 (2002) 1–101 7 1.5. Molecular, hybrid, and macromolecular materials The design, preparation, and study of physical properties of molecular assemblies and polymeric molecule-based materials exhibiting useful magnetic, electrical, or optical properties is a very active area of worldwide research. The quest in this area is not just to obtain molecule-based compounds than can behave like classical materials, but also to produce materials that may exhibit completely new physical properties or those in which several properties are combined. Examples of such sys￾tems could be materials showing electrical or magnetic bistability, tunable magnetic ordering temperatures, discrete molecules showing magnetic hysteresis (nanomagnets), and hybrid materials coupling more than one property, e.g. magnet￾ism with conductivity/superconductivity, or magnetism with optical properties. Other interesting phenomena that may be studied are quantum tunneling effects, long-lived photo-optical excited states, and solids with restricted magnetic dimensionalities. One frontier area in this research field is the evolution of new synthetic strategies to construct molecules at the mesoscale level and to specifically control their organi￾zation in solution and/or in the solid state. This includes the formation of thin layers and organized films, or their encapsulation/intercalation, etc., into solids. A second key area is the application of frontier experimental techniques to characterize the resulting materials and allow for the identification of the most interesting phenomena. Finally, it is important to develop suitable theoretical models based on solid-state approaches as well as on molecular orbital approaches (ab initio and density func￾tional theory). The ultimate goal is an understanding of the properties of the materials that will lead to predictions about the nature of interactions in molecular/macromolecular assemblies. All these areas of research have been, and continue to be, of great interest in the study of the solid state chemistry of non￾molecular compounds. There is an immeasurable potential benefit to both the solid state chemistry and molecular chemistry communities in greatly increasing the inter￾actions between these two areas of research. The structural and chemical diversity of molecular compounds is unparalleled in the world of solid state chemistry. Moreover, molecular compounds can be synthe￾sized by rational synthetic strategies that are impossible to implement in the solid state. In light of these attributes, molecular compounds present almost unlimited possibilities for development of new materials with novel and complex physical properties. The potential for fruitful interactions with the solid state chemistry com￾munity also appear to be limitless, as molecular chemists become increasingly inter￾ested in the synthesis of new compounds with exotic magnetic and electronic proper￾ties and the correlation of those properties with chemistry and structure—areas of research that are at the very heart of traditional solid state chemistry. This section describes the potential for interactions in the areas of molecular precursor routes to materials, self-assembled and organic materials, molecular nanomagnets, composite and hybrid molecular materials (such as templated materials) and finally inorganic/organic hybrid materials