Polyoxometalates (POMs) form a large, distinctive class of molecular inorganic compounds of unrivaled electronic versatility and structural variation, with impacts ranging from chemistry, catalysis, and materials science to biology, and medicine. This book covers the basic principles governing the structure, bonding and reactivity of these metal-oxygen cluster anions and the major developments in their molecular science.

The book comprises three sections. The first covers areas ranging from topological principles via synthesis and stability to reactivity in solution. It also focuses on the physical methods currently used to extract information on the molecular and electronic structures as well as the physical properties of these clusters. The second part reviews different types of POMs, focusing on those systems that currently impact other areas of interest, such as supramolecular chemistry, nanochemistry and molecular magnetism. The third section is devoted to POM-based materials and their applications and prospects in catalysis and materials science.

MICHAEL T. POPE AND ACHIM MULLER Department of Chemistry, Georgetown University, Washington, DC 20057-2222, U.S.A.; Department of Chemistry, University of Bielefeld, D-4BOO Bielefeld 1, F.R.G. Polyoxometalates, from their discovery and early development in the final decades of the 19th century to their current significance in disciplines as diverse as chemistry, mathematics, and medicine, continue to display surprisingly novel structures, unexpected reactivities and applications, and to attract increasing attention worldwide. Most of the contributors to the present volume participated in the workshop held at the Center for Interdisciplinary Research at the University of Bielefeld, July 15-17, 1992. The choice of topics illustrates some of the variety of directions and fields in which polyoxometalates can play an important role. Although many of the leading polyoxometalate research groups are represented here, we regret that time constraints, financial limitations, and in some cases difficulties of communication did not allow us to include significant and imp- tant work from other groups outside Europe and North America. In the following we briefly review the current status of the field of po- oxometalates.

This book provides an authoritative up-to-date summary of the chemistry and applications of polyoxometalates with emphasis on new synthetic strategies directed towards functionalized organic derivatives, self-assembly of mesoscopic composite polyoxoanions, generation of framework materials and thin oxide films, extended optical, magnetic, and electrical properties, applications in homogeneous and nanocluster-based catalysts, photocatalytic water decontamination, ribosomal crystallography, and topological aspects of large symmetrical structures.

Polyoxometalates are discrete early transition metal-oxide cluster anions and comprise a class of inorganic complexes of unrivaled versatility and structural variation in both symmetry and size, with applications in many fields of science. Recent findings of both electron-transfer processes and magnetic exchange-interactions in polyoxometalates with increasing nuclearities, topologies, and dimensionalities, and with combinations of different magnetic metal ions and/or organic moieties in the same lattice attract strong attention towards the design of nano-composites, since the assemblies of metal-oxide lattices ranging from insulators to superconductors form the basis of electronic devices and machines in present-day industries. The editors organized the symposium, "Polyoxometalate Chemistry for Nano-Composite Design" at the Pacifichem 2000 Congress, held in Honolulu on December 17-19, 2000. Chemists from several international polyoxometalate research groups discussed recent results, including: controlled self-organization processes for the preparation of nano-composites; electronic interactions in magnetic mixed-valence cryptands and coronands; synthesis of the novel polyoxometalates with topological or biological significance; systematic investigations in acid-base and/or redox catalysis for organic transformations; and electronic properties in materials science. It became evident during the symposium that the rapidly growing field of polyoxometalates has important properties pertinent to nano-composites. It is therefore easy for polyoxometalate chemists to envisage a "bottom-up" approach for their design starting from individual small-size molecules and moieties which possess their own functionalities relevant to electronic/magnetic devices (ferromagnetism, semiconductivity, prot- conductivity, and display), medicine (antitumoral, antiviral, and antimicrobacterial activities), and catalysis.

Combined oxygen, in the form of water, metal oxides, silicates and other oxyions, accounts for about 50% by weight of the earth's crust. The chemistry of this most abundant element has two major aspects: that of water and aqueous solutions of electrolytes, and that of the solid state. The methodology and techniques appropriate for the study of these fields are sufficiently different that there have been very few points of contact between solution- and solid state chemists. One such contact, of great potential value, is provided by the extensive class of polyoxoanions formed by the transition metals of groups 5 and 6. As 'heteropoly and isopoly acids' these polyanions have been known and investigated for more than a century. The pre sent book is an attempt to survey the chemistry, structures, and applications of these species. Although the book forms part of a series in inorganic chemistry, the field of polyoxometalates deserves wider attention, for example, from organic chemists, especially those concerned with homogeneous and heterogeneous catalysis, and from biochemists, solid state- and materials scientists."

An authoritative up-to-date summary of the chemistry and applications of polyoxometalates with emphasis on new synthetic strategies directed towards functionalized organic derivatives, self-assembly of mesoscopic composite polyoxoanions, generation of framework materials and thin oxide films, extended optical, magnetic, and electrical properties, applications in homogeneous and nanocluster-based catalysts, photocatalytic water decontamination, ribosomal crystallography, and topological aspects of large symmetrical structures.

Polyoxometalates (POMs) form a large, distinctive class of molecular inorganic compounds of unrivaled electronic versatility and structural variation, with impacts ranging from chemistry, catalysis, and materials science to biology, and medicine. This book covers the basic principles governing the structure, bonding and reactivity of these metal-oxygen cluster anions and the major developments in their molecular science.

The book comprises three sections. The first covers areas ranging from topological principles via synthesis and stability to reactivity in solution. It also focuses on the physical methods currently used to extract information on the molecular and electronic structures as well as the physical properties of these clusters. The second part reviews different types of POMs, focusing on those systems that currently impact other areas of interest, such as supramolecular chemistry, nanochemistry and molecular magnetism. The third section is devoted to POM-based materials and their applications and prospects in catalysis and materials science.